World Wide Web

World Wide Web

* World Wide Web is a library of resources available to computer users through the global Internet.

* It enables users to view a wide variety of information

* World Wide Web (WWW) resources are organized so that users can easily move from one resource to another.

* The connections to different source computers, or servers, on the network are made automatically without being seen by the user.

* These connections are made with the use of hypertext and hypermedia.

* Users generally navigate through information on the WWW with the aid of a program known as a WWW browser, or client.

* The browser presents text, images, sound, or other information objects on the user's computer screen in the form of a page, which is obtained from a WWW server.

* The user can navigate through information by pointing to specially designated text or other objects on the screen.

* These objects link the user to other WWW pages on the same server or on any other accessible WWW server on the network.

* The WWW links exist across the global Internet, forming a large-scale, distributed, multimedia knowledge base through related words, phrases, and images.

* Smaller-scale implementations are present on the enterprise Internets used by businesses.

* These implementations, known as "intranets" host private data and applications and can be protected from public access through a device known as a "firewall".

* WWW pages are formatted using Hypertext Markup Language (HTML), and WWW communication among computers uses the Hypertext Transfer Protocol (HTTP), or Wireless Access Protocol (WAP) for mobile phones.

* This communication is usually through the Internet via Transmission Control Protocol (TCP) connections, but almost any kind of connection can be used.

URL Format

* Uniform Resource Locator (URL), method of naming documents or places on the Internet, used most frequently on the World Wide Web (WWW).

* A URL is a string of characters that identifies the type of document, the computer the document is on, the directories and subdirectories the document is in, and the name of the document.

* http://www.open.gov.uk/services/standards.htm. The part of the URL before the colon represents the scheme, or format used to retrieve the document; http means the document is on the WWW.

Example

http://www.payne-gallway.co.uk/computing/student_resources.html

http:// Protocol

www Host

payne-gallway.co.uk Domain Name

computing Folder

student_resources.html Document Name

UK Codes

.ac academic institute

.co trading company

.gov government department

.org organisation (mostly non-profit)

.sch school

Browsers

* Browser, in computer science, a program that enables a computer to locate, download, and display documents containing text, sound, video, graphics, animation, and photographs located on computer networks.

* The act of viewing and moving about between documents on computer networks is called browsing.

* Users browse through documents on open, public-access networks called Internets, or on closed networks called intranets.

* The largest open network is the Internet, a worldwide computer network that provides access to sites on the World Wide Web (WWW or Web).

* Browsers allow users to access Web information by locating documents on remote computers that function as Web servers.

* A browser downloads information over phone lines to a user's computer through the user's modem, or other form of Web connection, and then displays the information on the computer.

* Most browsers can display a variety of text and graphics that may be integrated into such a document, including animation, audio, and video. Examples of browsers are Netscape Navigator, Internet Explorer, Mosaic, and Opera.

* Browsers can create the impression of travelling to an actual location in virtual space (hyperspace) where the document being viewed exists.

* This virtual location in hyperspace is referred to as a node, or a Web site.

* The process of virtual travel between Web sites is called navigating.

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