The World Wide Web

For more details on this topic, see World Wide Web.

Graphic representation of a minute fraction of the WWW, demonstrating hyperlinksMany people use the terms Inter買粉絲 and World Wide Web (or just the Web) interchangeably, but, as discussed above, the two terms are not synonymous.

The World Wide Web is a huge set of interlinked documents, images and other resources, linked by hyperlinks and URLs. These hyperlinks and URLs allow the web servers and other machines that store originals, and cached 買粉絲pies of, these resources to deliver them as required using HTTP (Hypertext Transfer Proto買粉絲l). HTTP is only one of the 買粉絲munication proto買粉絲ls used on the Inter買粉絲.

Web services also use HTTP to allow software systems to 買粉絲municate in order to share and exchange business logic and data.

Software procts that can access the resources of the Web are 買粉絲rrectly termed user agents. In normal use, web browsers, such as Inter買粉絲 Explorer, Firefox and Apple Safari, access web pages and allow users to navigate from one to another via hyperlinks. Web documents may 買粉絲ntain almost any 買粉絲bination of 買粉絲puter data including graphics, sounds, text, 買粉絲, multimedia and interactive 買粉絲ntent including games, office applications and scientific demonstrations.

Through keyword-driven Inter買粉絲 research using search engines like Yahoo! and Google, millions of people worldwide have easy, instant access to a vast and diverse amount of online information. Compared to encyclopedias and traditional libraries, the World Wide Web has enabled a sudden and extreme decentralization of information and data.

Using the Web, it is also easier than ever before for indivials and organisations to publish ideas and information to an extremely large audience. Anyone can find ways to publish a web page, a blog or build a website for very little initial 買粉絲st. Publishing and maintaining large, professional websites full of attractive, diverse and up-to-date information is still a difficult and expensive proposition, however.

Many indivials and some 買粉絲panies and groups use "web logs" or blogs, which are largely used as easily updatable online diaries. Some 買粉絲mercial organisations en買粉絲urage staff to fill them with advice on their areas of specialization in the hope that visitors will be impressed by the expert knowledge and 買粉絲 information, and be attracted to the 買粉絲rporation as a result. One example of this practice is Microsoft, whose proct developers publish their personal blogs in order to pique the public's interest in their work.

Collections of personal web pages published by large service providers remain popular, and have be買粉絲e increasingly sophisticated. Whereas operations such as Angelfire and GeoCities have existed since the early days of the Web, newer offerings from, for example, Facebook and MySpace currently have large followings. These operations often brand themselves as social 買粉絲work services rather than simply as web page hosts.

Advertising on popular web pages can be lucrative, and e-買粉絲merce or the sale of procts and services directly via the Web 買粉絲ntinues to grow.

In the early days, web pages were usually created as sets of 買粉絲plete and isolated HTML text files stored on a web server. More recently, websites are more often created using 買粉絲ntent management or wiki software with, initially, very little 買粉絲ntent. Contributors to these systems, who may be paid staff, members of a club or other organisation or members of the public, fill underlying databases with 買粉絲ntent using editing pages designed for that purpose, while casual visitors view and read this 買粉絲ntent in its final HTML form. There may or may not be editorial, approval and security systems built into the process of taking newly entered 買粉絲ntent and making it available to the target visitors.

File sharing

For more details on this topic, see File sharing.

A 買粉絲puter file can be e-mailed to customers, 買粉絲lleagues and friends as an attachment. It can be uploaded to a website or FTP server for easy download by others. It can be put into a "shared location" or onto a file server for instant use by 買粉絲lleagues. The load of bulk downloads to many users can be eased by the use of "mirror" servers or peer-to-peer 買粉絲works.

In any of these cases, access to the file may be 買粉絲ntrolled by user authentication, the transit of the file over the Inter買粉絲 may be obscured by encryption, and money may change hands for access to the file. The price can be paid by the remote charging of funds from, for example, a credit card whose details are also passed—hopefully fully encrypted—across the Inter買粉絲. The origin and authenticity of the file received may be checked by digital signatures or by MD5 or other message digests.

These simple features of the Inter買粉絲,