HTML & XHTML

Group 2 : Task 1

Group 2

—Origin of the World Wide Web

—Web Browser

—WWW vs Internet

—Uniform Resource Locator (URL)

Origin of the World Wide Web

—The Web allows computer to locate and view multimedia-based documents on almost any subject over the Internet .

—Tim Berners-Lee of CERN (European Organization for Nuclear Research) began to develop a technology for sharing information via hyperlink text documents .

—He also wrote communication protocol to form the backbone of his new information system , which he called the World Wide Web.

Web Browser

—A web browser or Internet browser is a software application for retrieving, presenting, and traversing information resources on the World Wide Web. An information resource is identified by a Uniform Resource Locator (URL) and may be a web page, image, video, or other piece of content. Hyperlinks present in resources enable users to easily navigate their browsers to related resources.

—Although browsers are primarily intended to access the World Wide Web, they can also be used to access information provided by Web servers in private networks or files in file systems. Some browsers can also be used to save information resources to file systems.

The History

The history of the web browser dates back in to the late 1980s, when a variety of technologies laid the foundation for the first Web browser, World Wide Web, by Tim Berners-Lee in 1991. That browser brought together a variety of existing and new software and hardware technologies.

—The NCSA Mosaic

—The introduction of the NCSA Mosaic Web browser in 1993 – one of the first graphical Web browsers – led to an explosion in Web use. Marc Andreessen, the leader of the Mosaic team at NCSA, soon started his own company, named Netscape, and released the Mosaic-influenced Netscape Navigator in 1994, which quickly became the world's most popular browser, accounting for 90% of all Web use at its peak.

—The Microsoft

—Microsoft responded with its browser Internet Explorer in 1995 (also heavily influenced by Mosaic), initiating the industry's first browser war. By bundling Internet Explorer with Windows, Microsoft was able to leverage its dominance in the operating system market to take over the Web browser market; Internet Explorer usage share peaked at over 95% by 2002. The usage share of Internet Explorer has declined from over 62.1% in January 2010 to 57.1% in December 2010 according to Net Applications, and it continues to decline.

—The Opera

—Opera first appeared in 1996; although it has never achieved widespread use, with a browser usage share that has fluctuated between 2.2% and 2.4% throughout 2010, it has a substantial share of the fast-growing mobile phone Web browser market, being preinstalled on over 40 million phones. It is also available on several other embedded systems, including Nintendo’s Wii video game console.

—The Mozilla Firefox

—In 1998, Netscape launched what was to become the Mozilla Foundation in an attempt to produce a competitive browser using the open source software model. That browser would eventually evolve into Firefox, which developed a respectable following while still in the beta stage of development; shortly after the release of Firefox 1.0 in late 2004, Firefox (all versions) accounted for 7.4% of browser use. The Firefox usage share has slowly declined in 2010, from 24.4% in January to 22.8% in December.

—The Apple’s Safari

—Apple's Safari had its first beta release in January 2003; it has a dominant share of Apple-based Web browsing, having risen from 4.5% usage share in January 2010 to 5.9% in December 2010. Its rendering engine, called WebKit, is also running in the standard browsers of several mobile phone platforms, including Apple iOS, Google Android, Nokia S60 and Palm webOS.

—The Google Chrome

—The most recent major entrant to the browser market is Google's WebKit-based Chrome, first released in September 2008. Its market share has quickly risen; its usage share has nearly doubled from 5.2% in January 2010 to 10.0% in December 2010, and appears to be gaining further in the coming months.

Function of Web Browser

—The primary purpose of a web browser is to bring information resources to the user. This process begins when the user inputs a Uniform Resource Identifier (URI), for example http://en.wikipedia.org/, into the browser. The prefix of the URI determines how the URI will be interpreted. The most commonly used kind of URI starts with http: and identifies a resource to be retrieved over the Hypertext Transfer Protocol (HTTP). Many browsers also support a variety of other prefixes, such as https: for HTTPS, ftp: for the File Transfer Protocol, and file: for local files.

What is The Internet

—The Internet is a massive network of networks, a networking infrastructure. It connects millions of computers together globally, forming a network in which any computer can communicate with any other computer as long as they are both connected to the Internet. Information that travels over the Internet does so via a variety of languages known as protocols.

Uniform Resource Locator

—In computing, a Uniform Resource Locator (URL) is a Uniform Resource Identifier (URI) that specifies where an identified resource is available and the mechanism for retrieving it. In popular usage and in many technical documents and verbal discussions it is often incorrectly used as a synonym for URI.[1] The best-known example of the use of URLs is for the addresses of web pages on the World Wide Web, such as http://www.example.com/

The History

—The Uniform Resource Locator was created in 1994 by Tim Berners-Lee and the URI working group of the Internet Engineering Task Force. The format is based on Unix file path syntax, where forward slashes are used to separate directory or folder and file or resource names. Conventions already existed where server names could be prepended to complete file paths, preceded by a double-slash (//).

—File formats may also be specified using a final dot suffix, so that requests for file.html or file.txt may be served directly whereas file.php needs to be sent to a PHP pre-processor before the processed result is served to the end user. The exposure of such implementation-specific details in public URLs is becoming less common; the necessary information can be better specified and exchanged using Internet media type identifiers, previously known as MIME types.

Syntax

—Every URL consists of some of the following: the scheme name (commonly called protocol), followed by a colon, then, depending on scheme, a domain name (alternatively, IP address), a port number, the path of the resource to be fetched or the program to be run, then, for programs such as Common Gateway Interface (CGI) scripts, a query string, and an optional fragment identifier.

—The syntax is scheme://domain:port/path?query_string#fragment_id.

—The scheme name defines the namespace, purpose, and the syntax of the remaining part of the URL. Software will try to process a URL according to its scheme and context. For example, a web browser will usually dereference the URL http://example.org:80 by performing an HTTP request to the host at example.org, using port number 80. The URL mailto:bob@example.com may start an e-mail composer with the address bob@example.com in the to field.