Showing posts with label World Wide Web. Show all posts
Showing posts with label World Wide Web. Show all posts

References

References

  1. ^ a b "Tim Berners Lee — Time 100 People of the Century". Time Magazine. Retrieved 17 May 2010. "He wove the World Wide Web and created a mass medium for the 21st century. The World Wide Web is Berners-Lee's alone. He designed it. He loosed it on the world. And he more than anyone else has fought to keep it open, nonproprietary and free. ."
  2. ^ "World Wide Web Consortium". "The World Wide Web Consortium (W3C)..."
  3. ^ a b c "Berners-Lee, Tim; Cailliau, Robert (November 12, 1990). "WorldWideWeb: Proposal for a hypertexts Project". Retrieved July 27, 2009.
  4. ^ Berners-Lee, Tim. "Pre-W3C Web and Internet Background". World Wide Web Consortium. Retrieved April 21, 2009.
  5. ^ Wardrip-Fruin, Noah and Nick Montfort, ed (2003). The New Media Reader. Section 54. The MIT Press. ISBN 0-262-23227-8.
  6. ^ von Braun, Wernher (May 1970). "TV Broadcast Satellite". Popular Science: 65–66. Retrieved January 12, 2011.
  7. ^ Berners-Lee, Tim (March 1989). "Information Management: A Proposal". W3C. Retrieved July 27, 2009.
  8. ^ "Tim Berners-Lee's original World Wide Web browser". "With recent phenomena like blogs and wikis, the web is beginning to develop the kind of collaborative nature that its inventor envisaged from the start."
  9. ^ "Tim Berners-Lee: client". W3.org. Retrieved July 27, 2009.
  10. ^ "First Web pages". W3.org. Retrieved July 27, 2009.
  11. ^ "Short summary of the World Wide Web project". Groups.google.com. August 6, 1991. Retrieved July 27, 2009.
  12. ^ Roads and Crossroads of Internet History by Gregory Gromov
  13. ^ "W3C timeline". Retrieved March 30, 2010.
  14. ^ "About SPIRES". Retrieved March 30, 2010.
  15. ^ "The Early World Wide Web at SLAC".
  16. ^ "A Little History of the World Wide Web".
  17. ^ "Inventor of the Week Archive: The World Wide Web". Massachusetts Institute of Technology: MIT School of Engineering. Retrieved July 23, 2009.

Caching

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 ask only 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 need to be refreshed only 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 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.

Speed issues

Speed issues

Frustration over congestion issues in the Internet infrastructure and the high latency that results in slow browsing has led to a pejorative name for the World Wide Web: the World Wide Wait.[78] Speeding up the Internet is an ongoing discussion over the use of peering and QoS technologies. Other solutions to reduce the congestion can be found at W3C.[79] Guidelines for Web response times are:[80]
  • 0.1 second (one tenth of a second). Ideal response time. The user does not 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.

Statistics

Statistics

Between 2005 and 2010, the number of Web users doubled, and was expected to surpass two billion in 2010.[71] According to a 2001 study, there were a massive number, over 550 billion, of documents on the Web, mostly in the invisible Web, or Deep Web.[72] A 2002 survey of 2,024 million Web pages[73] 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.[74] As of March 2009, the indexable web contains at least 25.21 billion pages.[75] On July 25, 2008, Google software engineers Jesse Alpert and Nissan Hajaj announced that Google Search had discovered one trillion unique URLs.[76] As of May 2009, over 109.5 million domains operated.[77][not in citation given] Of these 74% were commercial or other sites operating in the .com generic top-level domain.[77]
Statistics measuring a website's popularity are usually based either on the number of page views or on associated server 'hits' (file requests) that it receives.

Internationalization

The W3C Internationalization Activity assures that web technology will work in all languages, scripts, and cultures.[68] 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.[69] 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.[70]

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 or the aging population as their abilities change.[64] 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.[65] Tim Berners-Lee once noted, "The power of the Web is in its universality. Access by everyone regardless of disability is an essential aspect."[64] Many countries regulate web accessibility as a requirement for websites.[66] 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.[64][67]

Standards

Standards

Many formal standards and other technical specifications and software 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:
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.

Security

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.[51] Web-based vulnerabilities now outnumber traditional computer security concerns,[52][53] and as measured by Google, about one in ten web pages may contain malicious code.[54] Most Web-based attacks take place on legitimate websites, and most, as measured by Sophos, are hosted in the United States, China and Russia.[55] The most common of all malware threats is SQL injection attacks against websites.[56] Through HTML and URIs the Web was vulnerable to attacks like cross-site scripting (XSS) that came with the introduction of JavaScript[57] and were exacerbated to some degree by Web 2.0 and Ajax web design that favors the use of scripts.[58] Today by one estimate, 70% of all websites are open to XSS attacks on their users.[59]
Proposed solutions vary to extremes. Large security vendors like McAfee already design governance and compliance suites to meet post-9/11 regulations,[60] and some, like Finjan have recommended active real-time inspection of code and all content regardless of its source.[51] Some have argued that for enterprise to see security as a business opportunity rather than a cost center,[61] "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.[62] Jonathan Zittrain has said users sharing responsibility for computing safety is far preferable to locking down the Internet.[63]

Privacy

Privacy

It is possible that, average computer users who use the World Wide Web mainly for things like entertainment, may have surrendered the right to privacy in exchange for using a number of services available on the World Wide Web.[33][vague] For example: more than half a billion people worldwide have used a social network service,[34] and of the generations of people within the United States who have had access to the internet from a young age, half have some form of Social Networking presence.[35] and are part of a generational shift that could be changing norms.[36][37][further explanation needed] The social network Facebook progressed from

Http And Https Specifiers

http and https specifiers

The scheme specifiers (http:// or https://) in URIs refer to the Hypertext Transfer Protocol and to HTTP Secure, respectively, and so define the communication protocol to be used for the request and response. The HTTP protocol is fundamental to the operation of the World Wide Web; the added encryption layer in HTTPS is essential when confidential information such as passwords or banking information are to be exchanged over the public Internet. Web browsers usually prepend the scheme to URLs too, if omitted.

WWW prefix

WWW prefix

Many domain names used for the World Wide Web begin with www because of the long-standing practice of naming Internet hosts (servers) according to the services they provide. The hostname for a web server is often www, in the same way that it may be ftp for an FTP server, and news or nntp for a USENET news server. These host names appear as Domain Name System (DNS) subdomain names, as in www.example.com. The use of 'www' as a subdomain name is not required by any technical or policy standard; indeed, the first ever web server was called nxoc01.cern.ch,[27] and many web sites exist without it. Many established websites still use 'www', or they invent other subdomain names such as 'www2', 'secure', etc. Many such web servers are set up such that both the domain root (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 to different web sites.
The use of a subdomain name is useful for load balancing incoming web traffic by creating a CNAME record that points to a cluster of web servers. Since, currently, only a subdomain can be cname'ed, the same result cannot be achieved by using the bare domain root.

Linking

Linking

Most web pages contain hyperlinks to other related pages and perhaps to downloadable files, source documents, definitions and other web resources (this Wikipedia article is full of hyperlinks). In the underlying HTML, a hyperlink looks like
<a href="http://www.w3.org/History/19921103-hypertext/hypertext/WWW/">Early archive
 of the first Web site</a>
Graphic representation of a minute fraction of the WWW, demonstrating hyperlinks
Such a collection of useful, related resources, interconnected via hypertext links is dubbed a web of

Function

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 textual documents and other resources, linked by hyperlinks and URLs, transmitted by web browsers and web servers. In short, the Web can be thought of as an application "running" on the Internet.[24]
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. As an example, consider the Wikipedia page for this article with the URL http://en.wikipedia.org/wiki/World_Wide_Web .

History


In the June 1970 issue of Popular Science magazine Arthur C. Clarke was reported to have predicted that satellites would one day "bring the accumulated knowledge of the world to your fingertips" using a console that would combine the functionality of the Xerox, telephone, television and a small computer, allowing data transfer and video conferencing around the globe.[6]
In March 1989, Tim Berners-Lee wrote a proposal that referenced ENQUIRE, a database and software project he had built in 1980, and described a more elaborate information management system.[7]
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.[3] 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

World Wide Web

The World Wide Web (or the proper World-Wide Web; abbreviated as WWW or W3,[2] and commonly known as the Web) is a system of interlinked hypertext documents accessed via the Internet. With a web browser, one can view web pages that may contain text, images, videos, and other multimedia and navigate between them via hyperlinks.
Using concepts from earlier hypertext systems, British engineer and computer scientist Sir Tim Berners-Lee, now Director of the World Wide Web Consortium (W3C), wrote a proposal in March 1989 for what would eventually become the World Wide Web.[1] At CERN in Geneva, Switzerland, Berners-Lee and Belgian computer scientist Robert Cailliau proposed in 1990 to use hypertext "... to link and access information of various kinds as a web of nodes in which the user can browse at will",[3] and they publicly introduced the project in December.[4]
"The World-Wide Web was developed to be a pool of human knowledge, and human culture, which would allow collaborators in remote sites to share their ideas and all aspects of a common project.