Chapter 1
The Dark Lord Ascending
The two men appeared out of nowhere, a few yards apart in the narrow,
moonlit lane. For a second they stood quite still, wands directed
at each other’s chests; then, recognizing each other , they
stowed their wands beneath their cloaks and started walking briskly in the
same direction.
“News?� asked the taller of the two.
�The best,� replied Severus Snape.
The lane was bordered on the left by wild, low-growing brambles, on the
right by a high, nearly manicured hedge. The men’s long cloaks flapped around
their ankles as they marched.
“Thought I might be late,� said Yaxley, his blunt features sliding in and out
of sight as the branches of overhanging tress broke the moonlight. “It was
a little trickier than I expected. But I hope he will be satisfied. You should
confident that your reception will be good?�
Snape nodded, but did not elaborate. They turned right, into a wide driveway
that led off the lane. The high hedge curved into them, running off into the
distance beyond the pair of impressive wrought-iron gates barring the men’s
way. Neither of them broke step; In silence both raised their left arms in a
kind of salute and passed straight through, as though the dark metal weresmoke.
The yew hedges muffled the sound of the men’s footsteps. There was a
rustle somewhere to their right; Yaxley drew his wand again, pointing it over
his companion’s head, but the source of the noise proved to be nothing more
than a pure-white peacock, strutting majestically along the top of the hedge.
“He always did himself well, Lucius. Peacocks . . . � Yaxley thrust his wand
back under his cloak with a snort.
A handsome manor house grew out of the darkness at the end of the straight
drive, lights glinting in the diamond-paned downstairs windows. Somewhere
in the dark garden beyond the hedge a fountain was playing. Gravel crackled
beneath their feet as Snape and Yaxley sped toward the front door, which
swung inward at their approach, though nobody had visibly opened it.
The hallway was large, dimly light, and sumptuously decorated, with a
magnificent carpet covering most of the stone floor. The eyes of the pale-faced
portraits on the walls followed Snape and Yaxley as they strode past. The two
men halted at a heavy wooden door leading into the next room, hesitated for
the space of a heartbeat, then Snape turned the bronze handle.
The drawing room was full of silent people, sitting at a long and ornate
table. The room’s usual furniture had been pushed carelessly up against the
walls. Illumination came from a roaring fire beneath a handsome marble mantelpiece
surmounted by a gilded mirror. Snape and Yaxley lingered for a moment
on the threshold. As their eyes grew accustomed to the lack of light, they
were drawn upward to the strangest feature of the scenes an apparently unconscious
human figure hanging upside down over the table, revolving slowly as
if suspended by an invisible rope, and reflected in the mirror and in the bare,
polished surface of the table below it. He seemed unable to prevent himself
from glancing upward every minute or so.
“Yaxley, Snape,� said a high, clear voice from the head of the table. “You are
very nearly late.�
The speaker was seated directly in front of the fireplace, so that it was diffi-
cult, at first, for the new arrivals to make out more than his silhouette. As theydrew nearer, however, this face shone through the gloom, hairless, snakelike,
with slits for nostrils and gleaming red eyes whose pupils were vertical. He
was so pale that he seemed to emit a pearly glow.
“Severus, here,� said Voldemort, indication the seat on his immediate right.
“Yaxley—beside Dolohov.�
The two men took their allotted places. Most of the eyes around the table
followed Snape, and it was to him that Voldemort spoke first.
“So?�
“My Lord, the Order of the Phoenix intends to move Harry Potter from his
current place of safety on Saturday next, at nightfall.�
The interest around the table sharpened palpably; Some stiffened, others
fidgeted, all gazing at Snape and Voldemort.
“Saturday . . . at nightfall,� repeated Voldemort. His red eyes fastened upon
Snape’s black ones with such intensity that some of the watchers looked away,
apparently fearful that they themselves would be scorched by the ferocity of
the gaze. Snape, however, looked calmly back into Voldemort’s face and, after a
moment or two. Voldemort’s lipless mouth curved into something like a smile.
“Good. very good. And this information comes—�
“—from the source we discussed,� said Snape.
“My Lord.�
Yaxley had leaned forward to look down the long table at Voldemort and
Snape. All faces turned to him.
“My Lord, I have heard differently,�
Yaxley waited but Voldemort did not speak, so he went on, “Dawlish, the
Auror, let slip that Potter will not be moved until the thirtieth, the night before
the boy turns seventeen.�
Snape was smiling,
“My source told me that there are plans to lay a false trail; this must be it.
No doubt a Confundus Charm has been placed upon Dawlish. It would not be
the first time; he is known to be susceptible.�
“I assure you, my Lord, Dawlish seemed quite certain,� said Yaxley.
Read more here
Saturday, November 21, 2009
Top 5 Common Computer Problems and Solutions
If you own a computer, then you have probably encountered these computer problems before. Once you buy a computer, you must accept that sooner or later it will eventually crash due to a virus or some other massive error. If someone told you that your computer will last more than a decade, don't believe it because it is just a myth or another sales pitch. But of course, you should take care of it if you want it to last for its third year without any defects.
However, there are many people that would prefer to buy a new computer than spend some time trying to fix or figure out the problem with their laptop or desktop. Usually after the first two years, you will need some kind of maintenance because your computer will tend to lose its original speed and performance. Well, here are some if the common problems that a computer user usually experience.
You may ask why your computer has problems. To tell you frankly, most of the time the biggest problem that your computer has is YOU - the owner or the user. There are many people that neglect the first signs of computer problems. You shouldn't neglect those simple maintenance tasks that can enhance or prolong the life of your computer.
1. Computer speed or performance has slowed.
One of the things that computer owners usually notice is this. There are several reasons why this happens to your computer. Lack of maintenance, fragmented data, corrupted registry, spyware, and unnecessary loading of computer programs and services can surely affect your PC speed and performance. Managing your programs and cleaning your registry can easily boost your computer's performance speed up to 30%.
2. Computer system freezes and blue screens of death.
You need to do some serious diagnostic procedures to effectively know the problem with your computer. Computer virus or spyware are maybe some of the reasons why this is happening to your computer. Update your anti-spyware immediately to avoid this kind of problem and thoroughly scan your computer to see if it has any viruses or spywares. If you find that your computer is free from spyware then updating your hardware drive is the next step. Hardware drives makes it easier for your computer to effectively communicate with other hardware components. Without an updated driver the CPU locks up and may cause problems when you are using your computer. If that doesn't work try to increase your Computer RAM to help avoid computer freezes. By increasing the RAM you get more use out your computer's computing power.
3. The computer keeps on rebooting again and again.
This kind of problem is usually associated with hardware issue. Faulty power supply is usually the cause of this problem. Dirty or defective cooling fan is another reason why your computer is rebooting spontaneously. When your computer is trying to cool itself when the fan is defective it automatically switches off. Dust that accumulated in your computer can trap the heat inside which makes it hotter. What you should do is to clean the fan and make sure that it is running properly. Do not forget to check your power supply.
4. Noises and vibrations.
This one is almost certainly that your have hardware issue. High pitched noises can be caused by electronic components. Whatever the reason, you conduct a small investigation. Unplug your computer and remove the case and run the computer to discover the origin of noise. If a loose wire or faulty fan is not the one that is making the noise then it may be time to call a computer tech to help you with your problem.
5. Your browser home page changed itself.
It is known as "high-jacking" which is also caused by a Spyware installed on your system. The spyware in your computer installed a java script into your web browser that tells your browser to change settings hence changing the default home page of your browser. What you can do is to run an anti-virus or spyware program to remove the spyware from your computer.
All of the problems stated in this article can be avoided easily by simply maintaining your computer. Do not panic when you are experiencing a computer problem with your PC because the key to fixing that problem is to properly diagnose to identify what's happening to your computer. Take a few minutes to run some diagnostic test or seek help in computer forums before you rush out to computer technical center.
However, there are many people that would prefer to buy a new computer than spend some time trying to fix or figure out the problem with their laptop or desktop. Usually after the first two years, you will need some kind of maintenance because your computer will tend to lose its original speed and performance. Well, here are some if the common problems that a computer user usually experience.
You may ask why your computer has problems. To tell you frankly, most of the time the biggest problem that your computer has is YOU - the owner or the user. There are many people that neglect the first signs of computer problems. You shouldn't neglect those simple maintenance tasks that can enhance or prolong the life of your computer.
1. Computer speed or performance has slowed.
One of the things that computer owners usually notice is this. There are several reasons why this happens to your computer. Lack of maintenance, fragmented data, corrupted registry, spyware, and unnecessary loading of computer programs and services can surely affect your PC speed and performance. Managing your programs and cleaning your registry can easily boost your computer's performance speed up to 30%.
2. Computer system freezes and blue screens of death.
You need to do some serious diagnostic procedures to effectively know the problem with your computer. Computer virus or spyware are maybe some of the reasons why this is happening to your computer. Update your anti-spyware immediately to avoid this kind of problem and thoroughly scan your computer to see if it has any viruses or spywares. If you find that your computer is free from spyware then updating your hardware drive is the next step. Hardware drives makes it easier for your computer to effectively communicate with other hardware components. Without an updated driver the CPU locks up and may cause problems when you are using your computer. If that doesn't work try to increase your Computer RAM to help avoid computer freezes. By increasing the RAM you get more use out your computer's computing power.
3. The computer keeps on rebooting again and again.
This kind of problem is usually associated with hardware issue. Faulty power supply is usually the cause of this problem. Dirty or defective cooling fan is another reason why your computer is rebooting spontaneously. When your computer is trying to cool itself when the fan is defective it automatically switches off. Dust that accumulated in your computer can trap the heat inside which makes it hotter. What you should do is to clean the fan and make sure that it is running properly. Do not forget to check your power supply.
4. Noises and vibrations.
This one is almost certainly that your have hardware issue. High pitched noises can be caused by electronic components. Whatever the reason, you conduct a small investigation. Unplug your computer and remove the case and run the computer to discover the origin of noise. If a loose wire or faulty fan is not the one that is making the noise then it may be time to call a computer tech to help you with your problem.
5. Your browser home page changed itself.
It is known as "high-jacking" which is also caused by a Spyware installed on your system. The spyware in your computer installed a java script into your web browser that tells your browser to change settings hence changing the default home page of your browser. What you can do is to run an anti-virus or spyware program to remove the spyware from your computer.
All of the problems stated in this article can be avoided easily by simply maintaining your computer. Do not panic when you are experiencing a computer problem with your PC because the key to fixing that problem is to properly diagnose to identify what's happening to your computer. Take a few minutes to run some diagnostic test or seek help in computer forums before you rush out to computer technical center.
How to reinstall or repair internet explorer in Windows XP
Internet Explorer frequently crashes or picks up some toolbar that creates problems. Even malware may become embedded in Intenet Explorer.
Then one way out is to reinstall or repair the browser. And you can download and use Firefox instead.
Here is the link for Mozilla Firefox - a replacement for Internet Explorer. It has many extensions and plugins to make for a wholesome internet experience at the same time making the net safer (NoScript) and ad free (AdBlock plus)
Here is the method to reinstall Internet Explorer or repair it.
Don’t worry, just use Firefox from the link above.
Introduction
You may have to reinstall or to repair Internet Explorer in Windows XP if you have problems with Internet Explorer because of damaged files or missing registration information. You may also decide to reinstall or to repair Internet Explorer 6 to resolve problems with Outlook Express in Windows XP.
Methods to follow if you have Internet Explorer 6
Any of the methods in this article may resolve your problem. Feel free to select the one that you are most comfortable with.
Method 1: Install Internet Explorer 7
You may be able to resolve problems with Internet Explorer 6 if you install Internet Explorer 7. Installing Internet Explorer 7 probably will not resolve problems with Outlook Express.
For information about how to install Internet Explorer 7, visit the following Microsoft Web site:
http://www.microsoft.com/windows/products/winfamily/ie/default.mspx (http://www.microsoft.com/windows/products/winfamily/ie/default.mspx)
Note After you install Internet Explorer 7, you can repair damaged files or missing registration information in Internet Explorer 7. To do this, follow these steps:
1. Start Internet Explorer 7.
2. On the Tools menu, click Internet Options.
3. On the Advanced tab, click Reset.
4. In the Rest Internet Explorer Settings dialog box, click Reset to confirm.
Method 2: Install Windows XP Service Pack 2
If you do not want to install Internet Explorer 7, or for some reason cannot do so, you may be able to resolve problems with Internet Explorer 6 by installing Windows XP Service Pack 2. Additionally, installing Windows XP Service Pack 2 may help resolve issues with Outlook Express.
To install Windows XP Service Pack 2, follow these steps:
1. Visit the following Microsoft Web site:
(http://www.update.microsoft.com)
2. Click Express Install (Recommended).
3. If your computer qualifies, Windows XP Service Pack 2 will be one of the updates that is automatically selected. Click Install.
4. Review the Microsoft Software License Terms. Then, if you agree with it, accept it.
For more information how to obtain the latest Windows XP service pack, click the following article number to view the article in the Microsoft Knowledge Base:
322389 () How to obtain the latest Windows XP service pack
Method 3: Repair Internet Explorer 6 by using the System File Checker in Windows XP
If you already have Windows XP Service Pack 2 installed, and you do not want to install Internet Explorer 7, you may be able to resolve problems with Internet Explorer 6 by running the System File Checker. Additionally, running the System File Checker may help resolve issues with Outlook Express.
To run the System File Checker, follow these steps:
1. Click Start, click Run type sfc /scannow, and then press ENTER.
2. Follow the prompts throughout the System File Checker process.
3. Restart the computer when System File Checker process is complete.
Method 4: Reinstall Internet Explorer 6 by using the Ie.inf file
If you already have Windows XP Service Pack 2 installed, and you do not want to install Internet Explorer 7, you may be able to resolve problems with Internet Explorer 6 by using the Ie.inf file to reinstall Internet Explorer 6. To do this, follow these steps:
1. Click Start, click Run, type %systemroot%\inf, and then press Enter.
2. Find the Ie.inf file that is located in Windows\Inf folder.
3. Right-click the Ie.inf file, and then click Install.
4. Restart the computer when the file copy process is complete.
Method to follow if you have Internet Explorer 7
If you have Internet Explorer 7, you can repair damaged files or missing registration information in Internet Explorer 7. To do this, follow these steps:
1. Start Internet Explorer 7.
2. On the Tools menu, click Internet Options.
3. On the Advanced tab, click Reset.
4. In the Rest Internet Explorer Settings dialog box, click Reset to confirm.
Then one way out is to reinstall or repair the browser. And you can download and use Firefox instead.
Here is the link for Mozilla Firefox - a replacement for Internet Explorer. It has many extensions and plugins to make for a wholesome internet experience at the same time making the net safer (NoScript) and ad free (AdBlock plus)
Here is the method to reinstall Internet Explorer or repair it.
Don’t worry, just use Firefox from the link above.
Introduction
You may have to reinstall or to repair Internet Explorer in Windows XP if you have problems with Internet Explorer because of damaged files or missing registration information. You may also decide to reinstall or to repair Internet Explorer 6 to resolve problems with Outlook Express in Windows XP.
Methods to follow if you have Internet Explorer 6
Any of the methods in this article may resolve your problem. Feel free to select the one that you are most comfortable with.
Method 1: Install Internet Explorer 7
You may be able to resolve problems with Internet Explorer 6 if you install Internet Explorer 7. Installing Internet Explorer 7 probably will not resolve problems with Outlook Express.
For information about how to install Internet Explorer 7, visit the following Microsoft Web site:
http://www.microsoft.com/windows/products/winfamily/ie/default.mspx (http://www.microsoft.com/windows/products/winfamily/ie/default.mspx)
Note After you install Internet Explorer 7, you can repair damaged files or missing registration information in Internet Explorer 7. To do this, follow these steps:
1. Start Internet Explorer 7.
2. On the Tools menu, click Internet Options.
3. On the Advanced tab, click Reset.
4. In the Rest Internet Explorer Settings dialog box, click Reset to confirm.
Method 2: Install Windows XP Service Pack 2
If you do not want to install Internet Explorer 7, or for some reason cannot do so, you may be able to resolve problems with Internet Explorer 6 by installing Windows XP Service Pack 2. Additionally, installing Windows XP Service Pack 2 may help resolve issues with Outlook Express.
To install Windows XP Service Pack 2, follow these steps:
1. Visit the following Microsoft Web site:
(http://www.update.microsoft.com)
2. Click Express Install (Recommended).
3. If your computer qualifies, Windows XP Service Pack 2 will be one of the updates that is automatically selected. Click Install.
4. Review the Microsoft Software License Terms. Then, if you agree with it, accept it.
For more information how to obtain the latest Windows XP service pack, click the following article number to view the article in the Microsoft Knowledge Base:
322389 () How to obtain the latest Windows XP service pack
Method 3: Repair Internet Explorer 6 by using the System File Checker in Windows XP
If you already have Windows XP Service Pack 2 installed, and you do not want to install Internet Explorer 7, you may be able to resolve problems with Internet Explorer 6 by running the System File Checker. Additionally, running the System File Checker may help resolve issues with Outlook Express.
To run the System File Checker, follow these steps:
1. Click Start, click Run type sfc /scannow, and then press ENTER.
2. Follow the prompts throughout the System File Checker process.
3. Restart the computer when System File Checker process is complete.
Method 4: Reinstall Internet Explorer 6 by using the Ie.inf file
If you already have Windows XP Service Pack 2 installed, and you do not want to install Internet Explorer 7, you may be able to resolve problems with Internet Explorer 6 by using the Ie.inf file to reinstall Internet Explorer 6. To do this, follow these steps:
1. Click Start, click Run, type %systemroot%\inf, and then press Enter.
2. Find the Ie.inf file that is located in Windows\Inf folder.
3. Right-click the Ie.inf file, and then click Install.
4. Restart the computer when the file copy process is complete.
Method to follow if you have Internet Explorer 7
If you have Internet Explorer 7, you can repair damaged files or missing registration information in Internet Explorer 7. To do this, follow these steps:
1. Start Internet Explorer 7.
2. On the Tools menu, click Internet Options.
3. On the Advanced tab, click Reset.
4. In the Rest Internet Explorer Settings dialog box, click Reset to confirm.
Wednesday, November 4, 2009
World Wide Web
The World Wide Web is a system of interlinked hypertext documents contained on the Internet. With a web browser, one can view web pages that may contain text, images, videos, and other multimedia and navigate between them using hyperlinks. Using concepts from earlier hypertext systems, English physicist Tim Berners-Lee, now the Director of the World Wide Web Consortium, wrote a proposal in March 1989 for what would eventually become the World Wide Web.[1] He was later joined by Belgian computer scientist Robert Cailliau while both were working at CERN in Geneva, Switzerland. In 1990, they proposed using "HyperText [...] to link and access information of various kinds as a web of nodes in which the user can browse at will",[2] and released that web in December.[3]
"The World-Wide Web (W3) was developed to be a pool of human knowledge, which would allow collaborators in remote sites to share their ideas and all aspects of a common project." [4] If two projects are independently created. Rather than have a central figure make the changes, the two bodies of information could form into one cohesive piece of work.
History
Main article: History of the World Wide Web
This NeXT Computer used by Sir Tim Berners-Lee at CERN became the first web server.
In March 1989, Tim Berners-Lee wrote a proposal[5] that referenced ENQUIRE, a database and software project he had built in 1980, and described a more elaborate information management system. With help from Robert Cailliau, he published a more formal proposal (on November 12, 1990) to build a "Hypertext project" called "WorldWideWeb" (one word, also "W3") as a "web" of "hypertext documents" to be viewed by "browsers", using a client-server architecture.[2] This proposal estimated that a read-only web would be developed within three months and that it would take six months to achieve, "the creation of new links and new material by readers, [so that] authorship becomes universal" as well as "the automatic notification of a reader when new material of interest to him/her has become available". See Web 2.0 and RSS/Atom, which have taken a little longer to mature.
The proposal had been modeled after EBT's (Electronic Book Technology, a spin-off from the Institute for Research in Information and Scholarship at Brown University) Dynatext SGML reader that CERN had licensed. The Dynatext system, although technically advanced (a key player in the extension of SGML ISO 8879:1986 to Hypermedia within HyTime), was considered too expensive and with an inappropriate licensing policy for general HEP (High Energy Physics) community use: a fee for each document and each time a document was changed.
A NeXT Computer was used by Berners-Lee as the world's first web server and also to write the first web browser, WorldWideWeb, in 1990. By Christmas 1990, Berners-Lee had built all the tools necessary for a working Web:[6] the first web browser (which was a web editor as well), the first web server, and the first web pages[7] which described the project itself. On August 6, 1991, he posted a short summary of the World Wide Web project on the alt.hypertext newsgroup.[8] This date also marked the debut of the Web as a publicly available service on the Internet. The first server outside Europe was set up at SLAC in December 1991.[9] The crucial underlying concept of hypertext originated with older projects from the 1960s, such as the Hypertext Editing System (HES) at Brown University--- among others Ted Nelson and Andries van Dam--- Ted Nelson's Project Xanadu and Douglas Engelbart's oN-Line System (NLS). Both Nelson and Engelbart were in turn inspired by Vannevar Bush's microfilm-based "memex," which was described in the 1945 essay "As We May Think".[citation needed]
Berners-Lee's breakthrough was to marry hypertext to the Internet. In his book Weaving The Web, he explains that he had repeatedly suggested that a marriage between the two technologies was possible to members of both technical communities, but when no one took up his invitation, he finally tackled the project himself. In the process, he developed a system of globally unique identifiers for resources on the Web and elsewhere: the Universal Document Identifier (UDI) later known as Uniform Resource Locator (URL) and Uniform Resource Identifier (URI); and the publishing language HyperText Markup Language (HTML); and the Hypertext Transfer Protocol (HTTP).[10]
The World Wide Web had a number of differences from other hypertext systems that were then available. The Web required only unidirectional links rather than bidirectional ones. This made it possible for someone to link to another resource without action by the owner of that resource. It also significantly reduced the difficulty of implementing web servers and browsers (in comparison to earlier systems), but in turn presented the chronic problem of link rot. Unlike predecessors such as HyperCard, the World Wide Web was non-proprietary, making it possible to develop servers and clients independently and to add extensions without licensing restrictions. On April 30, 1993, CERN announced[11] that the World Wide Web would be free to anyone, with no fees due. Coming two months after the announcement that the Gopher protocol was no longer free to use, this produced a rapid shift away from Gopher and towards the Web. An early popular web browser was ViolaWWW, which was based upon HyperCard.
Scholars generally agree that a turning point for the World Wide Web began with the introduction[12] of the Mosaic web browser[13] in 1993, a graphical browser developed by a team at the National Center for Supercomputing Applications at the University of Illinois at Urbana-Champaign (NCSA-UIUC), led by Marc Andreessen. Funding for Mosaic came from the U.S. High-Performance Computing and Communications Initiative, a funding program initiated by the High Performance Computing and Communication Act of 1991, one of several computing developments initiated by U.S. Senator Al Gore.[14] Prior to the release of Mosaic, graphics were not commonly mixed with text in web pages, and its popularity was less than older protocols in use over the Internet, such as Gopher and Wide Area Information Servers (WAIS). Mosaic's graphical user interface allowed the Web to become, by far, the most popular Internet protocol.
The World Wide Web Consortium (W3C) was founded by Tim Berners-Lee after he left the European Organization for Nuclear Research (CERN) in October, 1994. It was founded at the Massachusetts Institute of Technology Laboratory for Computer Science (MIT/LCS) with support from the Defense Advanced Research Projects Agency (DARPA)—which had pioneered the Internet—and the European Commission. By the end of 1994, while the total number of websites was still minute compared to present standards, quite a number of notable websites were already active, many of whom are the precursors or inspiration for today's most popular services.
Connected by the existing Internet, other websites were created, around the world, adding international standards for domain names and the HTML. Since then, Berners-Lee has played an active role in guiding the development of web standards (such as the markup languages in which web pages are composed), and in recent years has advocated his vision of a Semantic Web. The World Wide Web enabled the spread of information over the Internet through an easy-to-use and flexible format. It thus played an important role in popularizing use of the Internet.[15] Although the two terms are sometimes conflated in popular use, World Wide Web is not synonymous with Internet.[16] The Web is an application built on top of the Internet.
The terms Internet and World Wide Web are often used in every-day speech without much distinction. However, the Internet and the World Wide Web are not one and the same. The Internet is a global system of interconnected computer networks. In contrast, the Web is one of the services that runs on the Internet. It is a collection of interconnected documents and other resources, linked by hyperlinks and URLs. In short, the Web is an application running on the Internet.[17] Viewing a web page on the World Wide Web normally begins either by typing the URL of the page into a web browser, or by following a hyperlink to that page or resource. The web browser then initiates a series of communication messages, behind the scenes, in order to fetch and display it.
First, the server-name portion of the URL is resolved into an IP address using the global, distributed Internet database known as the domain name system, or DNS. This IP address is necessary to contact the Web server. The browser then requests the resource by sending an HTTP request to the Web server at that particular address. In the case of a typical web page, the HTML text of the page is requested first and parsed immediately by the web browser, which then makes additional requests for images and any other files that form parts of the page. Statistics measuring a website's popularity are usually based either on the number of 'page views' or associated server 'hits' (file requests) that take place.
While receiving these files from the web server, browsers may progressively render the page onto the screen as specified by its HTML, CSS, and other web languages. Any images and other resources are incorporated to produce the on-screen web page that the user sees. Most web pages will themselves contain hyperlinks to other related pages and perhaps to downloads, source documents, definitions and other web resources. Such a collection of useful, related resources, interconnected via hypertext links, is what was dubbed a "web" of information. Making it available on the Internet created what Tim Berners-Lee first called the WorldWideWeb (in its original CamelCase, which was subsequently discarded) in November 1990.[2]
What Does W3 Define?
W3, or www, stands for many different things. The main topics being:
* The idea of a boundless information world in which all items have a reference by which they can be retrieved;
* the address system (URI) which the project implemented to make this world possible, despite many different protocols;
* a network protocol (HTTP) used by native W3 servers giving performance and features not otherwise available;
* a markup language (HTML) which every W3 client is required to understand, and is used for the transmission of basic things such as text, menus and simple on-line help information across the net;
* the body of data available on the Internet using all or some of the preceding listed items.
Linking
Graphic representation of a minute fraction of the WWW, demonstrating hyperlinks
Over time, many web resources pointed to by hyperlinks disappear, relocate, or are replaced with different content. This phenomenon is referred to in some circles as "link rot" and the hyperlinks affected by it are often called "dead links". The ephemeral nature of the Web has prompted many efforts to archive web sites. The Internet Archive is one of the best-known efforts; it has been active since 1996.
Ajax updates
Main article: Ajax (programming)
JavaScript is a scripting language that was initially developed in 1995 by Brendan Eich, then of Netscape, for use within web pages.[19] The standardized version is ECMAScript.[19] To overcome some of the limitations of the page-by-page model described above, some web applications also use Ajax (asynchronous JavaScript and XML). JavaScript is delivered with the page that can make additional HTTP requests to the server, either in response to user actions such as mouse-clicks, or based on lapsed time. The server's responses are used to modify the current page rather than creating a new page with each response. Thus the server only needs to provide limited, incremental information. Since multiple Ajax requests can be handled at the same time, users can interact with a page even while data is being retrieved. Some web applications regularly poll the server to ask if new information is available.[20]
WWW prefix
Many web addresses begin with www, because of the long-standing practice of naming Internet hosts (servers) according to the services they provide. So, the host name for a web server is often www as it is ftp for an FTP server, and news or nntp for a USENET news server etc. These host names then appear as DNS subdomain names, as in "www.example.com". The use of such subdomain names is not required by any technical or policy standard; indeed, the first ever web server was called "nxoc01.cern.ch",[21] and many web sites exist without a www subdomain prefix, or with some other prefix such as "www2", "secure" etc. These subdomain prefixes have no consequence; they are simply chosen names. Many web servers are set up such that both the domain by itself (e.g., example.com) and the www subdomain (e.g., www.example.com) refer to the same site, others require one form or the other, or they may map two different web sites.
When a single word is typed into the address bar and the return key is pressed, some web browsers automatically try adding "www." to the beginning of it and possibly ".com", ".org" and ".net" at the end. For example, typing 'apple' may resolve to http://www.apple.com/ and 'openoffice' to http://www.openoffice.org. This feature was beginning to be included in early versions of Mozilla Firefox (when it still had the working title 'Firebird') in early 2003.[22] It is reported that Microsoft was granted a US patent for the same idea in 2008, but only with regard to mobile devices.[23]
The 'http://' or 'https://' part of web addresses does have meaning: These refer to Hypertext Transfer Protocol and to HTTP Secure and so define the communication protocol that will be used to request and receive the page and all its images and other resources. The HTTP network protocol is fundamental to the way the World Wide Web works, and the encryption involved in HTTPS adds an essential layer if confidential information such as passwords or bank details are to be exchanged over the public internet. Web browsers often prepend this 'scheme' part to URLs too, if it is omitted. Despite this, Berners-Lee himself has admitted that the two 'forward slashes' (//) were in fact initially unnecessary[24]. In overview, RFC 2396 defined web URLs to have the following form:://?#. Here is for example the web server (like www.example.com), and identifies the web page. The web server processes the (which can be data sent via a form, e.g. terms sent to a search engine), and the returned page depends on it. Finally, is not sent to the web server. It identifies the portion of the page which the browser shows first.
In English, www is pronounced by individually pronouncing the name of characters (double-u double-u double-u). Although some technical users pronounce it dub-dub-dub this is not widespread. The English writer Douglas Adams once quipped in The Independent on Sunday (1999): "The World Wide Web is the only thing I know of whose shortened form takes three times longer to say than what it's short for," with Stephen Fry later pronouncing it in his "Podgrammes" series of podcasts as "wuh wuh wuh." It is also interesting that in Mandarin Chinese, World Wide Web is commonly translated via a phono-semantic matching to wàn wéi wǎng (万维网), which satisfies www and literally means "myriad dimensional net",[25] a translation that very appropriately reflects the design concept and proliferation of the World Wide Web. Tim Berners-Lee's web-space states that World Wide Web is officially spelled as three separate words, each capitalized, with no intervening hyphens.[26]
Safety
Privacy
Computer users, who save time and money, and who gain conveniences and entertainment, may or may not have surrendered the right to privacy in exchange for using a number of technologies including the Web.[27] Worldwide, more than a half billion people have used a social network service,[28] and of Americans who grew up with the Web, half created an online profile[29] and are part of a generational shift that could be changing norms.[30][31] Facebook progressed from U.S. college students to a 70% non-U.S. audience, and in 2009 prior to launching a beta test of the "transition tools" to set privacy preferences,[32] estimated that only 20% of its members use privacy settings.[33]
Privacy representatives from 60 countries have resolved to ask for laws to complement industry self-regulation, for education for children and other minors who use the Web, and for default protections for users of social networks.[34] They also believe data protection for personally identifiable information benefits business more than the sale of that information.[34] Users can opt-in to features in browsers to clear their personal histories locally and block some cookies and advertising networks[35] but they are still tracked in websites' server logs, and particularly web beacons.[36] Berners-Lee and colleagues see hope in accountability and appropriate use achieved by extending the Web's architecture to policy awareness, perhaps with audit logging, reasoners and appliances.[37] Among services paid for by advertising, Yahoo! could collect the most data about users of commercial websites, about 2,500 bits of information per month about each typical user of its site and its affiliated advertising network sites. Yahoo! was followed by MySpace with about half that potential and then by AOL–TimeWarner, Google, Facebook, Microsoft, and eBay.[38]
Security
The Web has become criminals' preferred pathway for spreading malware. Cybercrime carried out on the Web can include identity theft, fraud, espionage and intelligence gathering.[39] Web-based vulnerabilities now outnumber traditional computer security concerns,[40][41] and as measured by Google, about one in ten web pages may contain malicious code.[42] Most Web-based attacks take place on legitimate websites, and most, as measured by Sophos, are hosted in the United States, China and Russia.[43] The most common of all malware threats is SQL injection attacks against websites.[44] Through HTML and URIs the Web was vulnerable to attacks like cross-site scripting (XSS) that came with the introduction of JavaScript[45] and were exacerbated to some degree by Web 2.0 and Ajax web design that favors the use of scripts.[46] Today by one estimate, 70% of all websites are open to XSS attacks on their users.[47]
Proposed solutions vary to extremes. Large security vendors like McAfee already design governance and compliance suites to meet post-9/11 regulations,[48] and some, like Finjan have recommended active real-time inspection of code and all content regardless of its source.[39] Some have argued that for enterprise to see security as a business opportunity rather than a cost center,[49] "ubiquitous, always-on digital rights management" enforced in the infrastructure by a handful of organizations must replace the hundreds of companies that today secure data and networks.[50] Jonathan Zittrain has said users sharing responsibility for computing safety is far preferable to locking down the Internet.[51]
Availability
Standards
Main article: Web standards
Many formal standards and other technical specifications define the operation of different aspects of the World Wide Web, the Internet, and computer information exchange. Many of the documents are the work of the World Wide Web Consortium (W3C), headed by Berners-Lee, but some are produced by the Internet Engineering Task Force (IETF) and other organizations.
Usually, when web standards are discussed, the following publications are seen as foundational:
* Recommendations for markup languages, especially HTML and XHTML, from the W3C. These define the structure and interpretation of hypertext documents.
* Recommendations for stylesheets, especially CSS, from the W3C.
* Standards for ECMAScript (usually in the form of JavaScript), from Ecma International.
* Recommendations for the Document Object Model, from W3C.
Additional publications provide definitions of other essential technologies for the World Wide Web, including, but not limited to, the following:
* Uniform Resource Identifier (URI), which is a universal system for referencing resources on the Internet, such as hypertext documents and images. URIs, often called URLs, are defined by the IETF's RFC 3986 / STD 66: Uniform Resource Identifier (URI): Generic Syntax, as well as its predecessors and numerous URI scheme-defining RFCs;
* HyperText Transfer Protocol (HTTP), especially as defined by RFC 2616: HTTP/1.1 and RFC 2617: HTTP Authentication, which specify how the browser and server authenticate each other.
Accessibility
Main article: Web accessibility
Access to the Web is for everyone regardless of disability including visual, auditory, physical, speech, cognitive, and neurological. Accessibility features also help others with temporary disabilities like a broken arm and an ageing population as their abilities change.[52] The Web is used for receiving information as well as providing information and interacting with society, making it essential that the Web be accessible in order to provide equal access and equal opportunity to people with disabilities.[53] Tim Berners-Lee once noted, "The power of the Web is in its universality. Access by everyone regardless of disability is an essential aspect."[52] Many countries regulate web accessibility as a requirement for websites.[54] International cooperation in the W3C Web Accessibility Initiative led to simple guidelines that web content authors as well as software developers can use to make the Web accessible to persons who may or may not be using assistive technology.[52][55]
Internationalization
The W3C Internationalization Activity assures that web technology will work in all languages, scripts, and cultures.[56] Beginning in 2004 or 2005, Unicode gained ground and eventually in December 2007 surpassed both ASCII and Western European as the Web's most frequently used character encoding.[57] Originally RFC 3986 allowed resources to be identified by URI in a subset of US-ASCII. RFC 3987 allows more characters—any character in the Universal Character Set—and now a resource can be identified by IRI in any language.[58]
Statistics
According to a 2001 study, there were massively more than 550 billion documents on the Web, mostly in the invisible Web, or deep Web.[59] A 2002 survey of 2,024 million Web pages[60] determined that by far the most Web content was in English: 56.4%; next were pages in German (7.7%), French (5.6%), and Japanese (4.9%). A more recent study, which used Web searches in 75 different languages to sample the Web, determined that there were over 11.5 billion Web pages in the publicly indexable Web as of the end of January 2005.[61] As of March 2009[update], the indexable web contains at least 25.21 billion pages.[62] On July 25, 2008, Google software engineers Jesse Alpert and Nissan Hajaj announced that Google Search had discovered one trillion unique URLs.[63] As of May 2009[update], over 109.5 million websites operated.[64] Of these 74% were commercial or other sites operating in the .com generic top-level domain.[64]
Technology
Speed issues
Frustration over congestion issues in the Internet infrastructure and the high latency that results in slow browsing has led to an alternative, pejorative name for the World Wide Web: the World Wide Wait.[65] Speeding up the Internet is an ongoing discussion over the use of peering and QoS technologies. Other solutions to reduce the World Wide Wait can be found at W3C.[66] Standard guidelines for ideal Web response times are:[67]
* 0.1 second (one tenth of a second). Ideal response time. The user doesn't sense any interruption.
* 1 second. Highest acceptable response time. Download times above 1 second interrupt the user experience.
* 10 seconds. Unacceptable response time. The user experience is interrupted and the user is likely to leave the site or system.
Caching
If a user revisits a Web page after only a short interval, the page data may not need to be re-obtained from the source Web server. Almost all web browsers cache recently obtained data, usually on the local hard drive. HTTP requests sent by a browser will usually only ask for data that has changed since the last download. If the locally cached data are still current, it will be reused. Caching helps reduce the amount of Web traffic on the Internet. The decision about expiration is made independently for each downloaded file, whether image, stylesheet, JavaScript, HTML, or whatever other content the site may provide. Thus even on sites with highly dynamic content, many of the basic resources only need to be refreshed occasionally. Web site designers find it worthwhile to collate resources such as CSS data and JavaScript into a few site-wide files so that they can be cached efficiently. This helps reduce page download times and lowers demands on the Web server.
There are other components of the Internet that can cache Web content. Corporate and academic firewalls often cache Web resources requested by one user for the benefit of all. (See also Caching proxy server.) Some search engines, such as Google or Yahoo!, also store cached content from websites. Apart from the facilities built into Web servers that can determine when files have been updated and so need to be re-sent, designers of dynamically generated Web pages can control the HTTP headers sent back to requesting users, so that transient or sensitive pages are not cached. Internet banking and news sites frequently use this facility. Data requested with an HTTP 'GET' is likely to be cached if other conditions are met; data obtained in response to a 'POST' is assumed to depend on the data that was POSTed and so is not cached.
"The World-Wide Web (W3) was developed to be a pool of human knowledge, which would allow collaborators in remote sites to share their ideas and all aspects of a common project." [4] If two projects are independently created. Rather than have a central figure make the changes, the two bodies of information could form into one cohesive piece of work.
History
Main article: History of the World Wide Web
This NeXT Computer used by Sir Tim Berners-Lee at CERN became the first web server.
In March 1989, Tim Berners-Lee wrote a proposal[5] that referenced ENQUIRE, a database and software project he had built in 1980, and described a more elaborate information management system. With help from Robert Cailliau, he published a more formal proposal (on November 12, 1990) to build a "Hypertext project" called "WorldWideWeb" (one word, also "W3") as a "web" of "hypertext documents" to be viewed by "browsers", using a client-server architecture.[2] This proposal estimated that a read-only web would be developed within three months and that it would take six months to achieve, "the creation of new links and new material by readers, [so that] authorship becomes universal" as well as "the automatic notification of a reader when new material of interest to him/her has become available". See Web 2.0 and RSS/Atom, which have taken a little longer to mature.
The proposal had been modeled after EBT's (Electronic Book Technology, a spin-off from the Institute for Research in Information and Scholarship at Brown University) Dynatext SGML reader that CERN had licensed. The Dynatext system, although technically advanced (a key player in the extension of SGML ISO 8879:1986 to Hypermedia within HyTime), was considered too expensive and with an inappropriate licensing policy for general HEP (High Energy Physics) community use: a fee for each document and each time a document was changed.
A NeXT Computer was used by Berners-Lee as the world's first web server and also to write the first web browser, WorldWideWeb, in 1990. By Christmas 1990, Berners-Lee had built all the tools necessary for a working Web:[6] the first web browser (which was a web editor as well), the first web server, and the first web pages[7] which described the project itself. On August 6, 1991, he posted a short summary of the World Wide Web project on the alt.hypertext newsgroup.[8] This date also marked the debut of the Web as a publicly available service on the Internet. The first server outside Europe was set up at SLAC in December 1991.[9] The crucial underlying concept of hypertext originated with older projects from the 1960s, such as the Hypertext Editing System (HES) at Brown University--- among others Ted Nelson and Andries van Dam--- Ted Nelson's Project Xanadu and Douglas Engelbart's oN-Line System (NLS). Both Nelson and Engelbart were in turn inspired by Vannevar Bush's microfilm-based "memex," which was described in the 1945 essay "As We May Think".[citation needed]
Berners-Lee's breakthrough was to marry hypertext to the Internet. In his book Weaving The Web, he explains that he had repeatedly suggested that a marriage between the two technologies was possible to members of both technical communities, but when no one took up his invitation, he finally tackled the project himself. In the process, he developed a system of globally unique identifiers for resources on the Web and elsewhere: the Universal Document Identifier (UDI) later known as Uniform Resource Locator (URL) and Uniform Resource Identifier (URI); and the publishing language HyperText Markup Language (HTML); and the Hypertext Transfer Protocol (HTTP).[10]
The World Wide Web had a number of differences from other hypertext systems that were then available. The Web required only unidirectional links rather than bidirectional ones. This made it possible for someone to link to another resource without action by the owner of that resource. It also significantly reduced the difficulty of implementing web servers and browsers (in comparison to earlier systems), but in turn presented the chronic problem of link rot. Unlike predecessors such as HyperCard, the World Wide Web was non-proprietary, making it possible to develop servers and clients independently and to add extensions without licensing restrictions. On April 30, 1993, CERN announced[11] that the World Wide Web would be free to anyone, with no fees due. Coming two months after the announcement that the Gopher protocol was no longer free to use, this produced a rapid shift away from Gopher and towards the Web. An early popular web browser was ViolaWWW, which was based upon HyperCard.
Scholars generally agree that a turning point for the World Wide Web began with the introduction[12] of the Mosaic web browser[13] in 1993, a graphical browser developed by a team at the National Center for Supercomputing Applications at the University of Illinois at Urbana-Champaign (NCSA-UIUC), led by Marc Andreessen. Funding for Mosaic came from the U.S. High-Performance Computing and Communications Initiative, a funding program initiated by the High Performance Computing and Communication Act of 1991, one of several computing developments initiated by U.S. Senator Al Gore.[14] Prior to the release of Mosaic, graphics were not commonly mixed with text in web pages, and its popularity was less than older protocols in use over the Internet, such as Gopher and Wide Area Information Servers (WAIS). Mosaic's graphical user interface allowed the Web to become, by far, the most popular Internet protocol.
The World Wide Web Consortium (W3C) was founded by Tim Berners-Lee after he left the European Organization for Nuclear Research (CERN) in October, 1994. It was founded at the Massachusetts Institute of Technology Laboratory for Computer Science (MIT/LCS) with support from the Defense Advanced Research Projects Agency (DARPA)—which had pioneered the Internet—and the European Commission. By the end of 1994, while the total number of websites was still minute compared to present standards, quite a number of notable websites were already active, many of whom are the precursors or inspiration for today's most popular services.
Connected by the existing Internet, other websites were created, around the world, adding international standards for domain names and the HTML. Since then, Berners-Lee has played an active role in guiding the development of web standards (such as the markup languages in which web pages are composed), and in recent years has advocated his vision of a Semantic Web. The World Wide Web enabled the spread of information over the Internet through an easy-to-use and flexible format. It thus played an important role in popularizing use of the Internet.[15] Although the two terms are sometimes conflated in popular use, World Wide Web is not synonymous with Internet.[16] The Web is an application built on top of the Internet.
The terms Internet and World Wide Web are often used in every-day speech without much distinction. However, the Internet and the World Wide Web are not one and the same. The Internet is a global system of interconnected computer networks. In contrast, the Web is one of the services that runs on the Internet. It is a collection of interconnected documents and other resources, linked by hyperlinks and URLs. In short, the Web is an application running on the Internet.[17] Viewing a web page on the World Wide Web normally begins either by typing the URL of the page into a web browser, or by following a hyperlink to that page or resource. The web browser then initiates a series of communication messages, behind the scenes, in order to fetch and display it.
First, the server-name portion of the URL is resolved into an IP address using the global, distributed Internet database known as the domain name system, or DNS. This IP address is necessary to contact the Web server. The browser then requests the resource by sending an HTTP request to the Web server at that particular address. In the case of a typical web page, the HTML text of the page is requested first and parsed immediately by the web browser, which then makes additional requests for images and any other files that form parts of the page. Statistics measuring a website's popularity are usually based either on the number of 'page views' or associated server 'hits' (file requests) that take place.
While receiving these files from the web server, browsers may progressively render the page onto the screen as specified by its HTML, CSS, and other web languages. Any images and other resources are incorporated to produce the on-screen web page that the user sees. Most web pages will themselves contain hyperlinks to other related pages and perhaps to downloads, source documents, definitions and other web resources. Such a collection of useful, related resources, interconnected via hypertext links, is what was dubbed a "web" of information. Making it available on the Internet created what Tim Berners-Lee first called the WorldWideWeb (in its original CamelCase, which was subsequently discarded) in November 1990.[2]
What Does W3 Define?
W3, or www, stands for many different things. The main topics being:
* The idea of a boundless information world in which all items have a reference by which they can be retrieved;
* the address system (URI) which the project implemented to make this world possible, despite many different protocols;
* a network protocol (HTTP) used by native W3 servers giving performance and features not otherwise available;
* a markup language (HTML) which every W3 client is required to understand, and is used for the transmission of basic things such as text, menus and simple on-line help information across the net;
* the body of data available on the Internet using all or some of the preceding listed items.
Linking
Graphic representation of a minute fraction of the WWW, demonstrating hyperlinks
Over time, many web resources pointed to by hyperlinks disappear, relocate, or are replaced with different content. This phenomenon is referred to in some circles as "link rot" and the hyperlinks affected by it are often called "dead links". The ephemeral nature of the Web has prompted many efforts to archive web sites. The Internet Archive is one of the best-known efforts; it has been active since 1996.
Ajax updates
Main article: Ajax (programming)
JavaScript is a scripting language that was initially developed in 1995 by Brendan Eich, then of Netscape, for use within web pages.[19] The standardized version is ECMAScript.[19] To overcome some of the limitations of the page-by-page model described above, some web applications also use Ajax (asynchronous JavaScript and XML). JavaScript is delivered with the page that can make additional HTTP requests to the server, either in response to user actions such as mouse-clicks, or based on lapsed time. The server's responses are used to modify the current page rather than creating a new page with each response. Thus the server only needs to provide limited, incremental information. Since multiple Ajax requests can be handled at the same time, users can interact with a page even while data is being retrieved. Some web applications regularly poll the server to ask if new information is available.[20]
WWW prefix
Many web addresses begin with www, because of the long-standing practice of naming Internet hosts (servers) according to the services they provide. So, the host name for a web server is often www as it is ftp for an FTP server, and news or nntp for a USENET news server etc. These host names then appear as DNS subdomain names, as in "www.example.com". The use of such subdomain names is not required by any technical or policy standard; indeed, the first ever web server was called "nxoc01.cern.ch",[21] and many web sites exist without a www subdomain prefix, or with some other prefix such as "www2", "secure" etc. These subdomain prefixes have no consequence; they are simply chosen names. Many web servers are set up such that both the domain by itself (e.g., example.com) and the www subdomain (e.g., www.example.com) refer to the same site, others require one form or the other, or they may map two different web sites.
When a single word is typed into the address bar and the return key is pressed, some web browsers automatically try adding "www." to the beginning of it and possibly ".com", ".org" and ".net" at the end. For example, typing 'apple
The 'http://' or 'https://' part of web addresses does have meaning: These refer to Hypertext Transfer Protocol and to HTTP Secure and so define the communication protocol that will be used to request and receive the page and all its images and other resources. The HTTP network protocol is fundamental to the way the World Wide Web works, and the encryption involved in HTTPS adds an essential layer if confidential information such as passwords or bank details are to be exchanged over the public internet. Web browsers often prepend this 'scheme' part to URLs too, if it is omitted. Despite this, Berners-Lee himself has admitted that the two 'forward slashes' (//) were in fact initially unnecessary[24]. In overview, RFC 2396 defined web URLs to have the following form:
In English, www is pronounced by individually pronouncing the name of characters (double-u double-u double-u). Although some technical users pronounce it dub-dub-dub this is not widespread. The English writer Douglas Adams once quipped in The Independent on Sunday (1999): "The World Wide Web is the only thing I know of whose shortened form takes three times longer to say than what it's short for," with Stephen Fry later pronouncing it in his "Podgrammes" series of podcasts as "wuh wuh wuh." It is also interesting that in Mandarin Chinese, World Wide Web is commonly translated via a phono-semantic matching to wàn wéi wǎng (万维网), which satisfies www and literally means "myriad dimensional net",[25] a translation that very appropriately reflects the design concept and proliferation of the World Wide Web. Tim Berners-Lee's web-space states that World Wide Web is officially spelled as three separate words, each capitalized, with no intervening hyphens.[26]
Safety
Privacy
Computer users, who save time and money, and who gain conveniences and entertainment, may or may not have surrendered the right to privacy in exchange for using a number of technologies including the Web.[27] Worldwide, more than a half billion people have used a social network service,[28] and of Americans who grew up with the Web, half created an online profile[29] and are part of a generational shift that could be changing norms.[30][31] Facebook progressed from U.S. college students to a 70% non-U.S. audience, and in 2009 prior to launching a beta test of the "transition tools" to set privacy preferences,[32] estimated that only 20% of its members use privacy settings.[33]
Privacy representatives from 60 countries have resolved to ask for laws to complement industry self-regulation, for education for children and other minors who use the Web, and for default protections for users of social networks.[34] They also believe data protection for personally identifiable information benefits business more than the sale of that information.[34] Users can opt-in to features in browsers to clear their personal histories locally and block some cookies and advertising networks[35] but they are still tracked in websites' server logs, and particularly web beacons.[36] Berners-Lee and colleagues see hope in accountability and appropriate use achieved by extending the Web's architecture to policy awareness, perhaps with audit logging, reasoners and appliances.[37] Among services paid for by advertising, Yahoo! could collect the most data about users of commercial websites, about 2,500 bits of information per month about each typical user of its site and its affiliated advertising network sites. Yahoo! was followed by MySpace with about half that potential and then by AOL–TimeWarner, Google, Facebook, Microsoft, and eBay.[38]
Security
The Web has become criminals' preferred pathway for spreading malware. Cybercrime carried out on the Web can include identity theft, fraud, espionage and intelligence gathering.[39] Web-based vulnerabilities now outnumber traditional computer security concerns,[40][41] and as measured by Google, about one in ten web pages may contain malicious code.[42] Most Web-based attacks take place on legitimate websites, and most, as measured by Sophos, are hosted in the United States, China and Russia.[43] The most common of all malware threats is SQL injection attacks against websites.[44] Through HTML and URIs the Web was vulnerable to attacks like cross-site scripting (XSS) that came with the introduction of JavaScript[45] and were exacerbated to some degree by Web 2.0 and Ajax web design that favors the use of scripts.[46] Today by one estimate, 70% of all websites are open to XSS attacks on their users.[47]
Proposed solutions vary to extremes. Large security vendors like McAfee already design governance and compliance suites to meet post-9/11 regulations,[48] and some, like Finjan have recommended active real-time inspection of code and all content regardless of its source.[39] Some have argued that for enterprise to see security as a business opportunity rather than a cost center,[49] "ubiquitous, always-on digital rights management" enforced in the infrastructure by a handful of organizations must replace the hundreds of companies that today secure data and networks.[50] Jonathan Zittrain has said users sharing responsibility for computing safety is far preferable to locking down the Internet.[51]
Availability
Standards
Main article: Web standards
Many formal standards and other technical specifications define the operation of different aspects of the World Wide Web, the Internet, and computer information exchange. Many of the documents are the work of the World Wide Web Consortium (W3C), headed by Berners-Lee, but some are produced by the Internet Engineering Task Force (IETF) and other organizations.
Usually, when web standards are discussed, the following publications are seen as foundational:
* Recommendations for markup languages, especially HTML and XHTML, from the W3C. These define the structure and interpretation of hypertext documents.
* Recommendations for stylesheets, especially CSS, from the W3C.
* Standards for ECMAScript (usually in the form of JavaScript), from Ecma International.
* Recommendations for the Document Object Model, from W3C.
Additional publications provide definitions of other essential technologies for the World Wide Web, including, but not limited to, the following:
* Uniform Resource Identifier (URI), which is a universal system for referencing resources on the Internet, such as hypertext documents and images. URIs, often called URLs, are defined by the IETF's RFC 3986 / STD 66: Uniform Resource Identifier (URI): Generic Syntax, as well as its predecessors and numerous URI scheme-defining RFCs;
* HyperText Transfer Protocol (HTTP), especially as defined by RFC 2616: HTTP/1.1 and RFC 2617: HTTP Authentication, which specify how the browser and server authenticate each other.
Accessibility
Main article: Web accessibility
Access to the Web is for everyone regardless of disability including visual, auditory, physical, speech, cognitive, and neurological. Accessibility features also help others with temporary disabilities like a broken arm and an ageing population as their abilities change.[52] The Web is used for receiving information as well as providing information and interacting with society, making it essential that the Web be accessible in order to provide equal access and equal opportunity to people with disabilities.[53] Tim Berners-Lee once noted, "The power of the Web is in its universality. Access by everyone regardless of disability is an essential aspect."[52] Many countries regulate web accessibility as a requirement for websites.[54] International cooperation in the W3C Web Accessibility Initiative led to simple guidelines that web content authors as well as software developers can use to make the Web accessible to persons who may or may not be using assistive technology.[52][55]
Internationalization
The W3C Internationalization Activity assures that web technology will work in all languages, scripts, and cultures.[56] Beginning in 2004 or 2005, Unicode gained ground and eventually in December 2007 surpassed both ASCII and Western European as the Web's most frequently used character encoding.[57] Originally RFC 3986 allowed resources to be identified by URI in a subset of US-ASCII. RFC 3987 allows more characters—any character in the Universal Character Set—and now a resource can be identified by IRI in any language.[58]
Statistics
According to a 2001 study, there were massively more than 550 billion documents on the Web, mostly in the invisible Web, or deep Web.[59] A 2002 survey of 2,024 million Web pages[60] determined that by far the most Web content was in English: 56.4%; next were pages in German (7.7%), French (5.6%), and Japanese (4.9%). A more recent study, which used Web searches in 75 different languages to sample the Web, determined that there were over 11.5 billion Web pages in the publicly indexable Web as of the end of January 2005.[61] As of March 2009[update], the indexable web contains at least 25.21 billion pages.[62] On July 25, 2008, Google software engineers Jesse Alpert and Nissan Hajaj announced that Google Search had discovered one trillion unique URLs.[63] As of May 2009[update], over 109.5 million websites operated.[64] Of these 74% were commercial or other sites operating in the .com generic top-level domain.[64]
Technology
Speed issues
Frustration over congestion issues in the Internet infrastructure and the high latency that results in slow browsing has led to an alternative, pejorative name for the World Wide Web: the World Wide Wait.[65] Speeding up the Internet is an ongoing discussion over the use of peering and QoS technologies. Other solutions to reduce the World Wide Wait can be found at W3C.[66] Standard guidelines for ideal Web response times are:[67]
* 0.1 second (one tenth of a second). Ideal response time. The user doesn't sense any interruption.
* 1 second. Highest acceptable response time. Download times above 1 second interrupt the user experience.
* 10 seconds. Unacceptable response time. The user experience is interrupted and the user is likely to leave the site or system.
Caching
If a user revisits a Web page after only a short interval, the page data may not need to be re-obtained from the source Web server. Almost all web browsers cache recently obtained data, usually on the local hard drive. HTTP requests sent by a browser will usually only ask for data that has changed since the last download. If the locally cached data are still current, it will be reused. Caching helps reduce the amount of Web traffic on the Internet. The decision about expiration is made independently for each downloaded file, whether image, stylesheet, JavaScript, HTML, or whatever other content the site may provide. Thus even on sites with highly dynamic content, many of the basic resources only need to be refreshed occasionally. Web site designers find it worthwhile to collate resources such as CSS data and JavaScript into a few site-wide files so that they can be cached efficiently. This helps reduce page download times and lowers demands on the Web server.
There are other components of the Internet that can cache Web content. Corporate and academic firewalls often cache Web resources requested by one user for the benefit of all. (See also Caching proxy server.) Some search engines, such as Google or Yahoo!, also store cached content from websites. Apart from the facilities built into Web servers that can determine when files have been updated and so need to be re-sent, designers of dynamically generated Web pages can control the HTTP headers sent back to requesting users, so that transient or sensitive pages are not cached. Internet banking and news sites frequently use this facility. Data requested with an HTTP 'GET' is likely to be cached if other conditions are met; data obtained in response to a 'POST' is assumed to depend on the data that was POSTed and so is not cached.
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