Internet

The is a global collection of , , , applications, and other resources, logically interrelated by and referenced with (URIs), which provide a global system of named references. URIs symbolically identify services, , databases, and the documents and resources that they can provide. (HTTP) is the main access protocol of the World Wide Web. also use HTTP for communication between software systems for information transfer, sharing and exchanging business data and logistic and is one of many languages or protocols that can be used for communication on the Internet.[79]

World Wide Web browser software, such as 's /, , , 's , and , lets users navigate from one web page to another via the hyperlinks embedded in the documents. These documents may also contain any combination of , including graphics, sounds, , , and interactive content that runs while the user is interacting with the page. can include animations, , and scientific demonstrations. Through -driven using like , and , users worldwide have easy, instant access to a vast and diverse amount of online information. Compared to printed media, books, encyclopedias and traditional libraries, the World Wide Web has enabled the decentralization of information on a large scale.

The Web has enabled individuals and organizations to ideas and information to a potentially large online at greatly reduced expense and time delay. Publishing a web page, a blog, or building a website involves little initial and many cost-free services are available. However, publishing and maintaining large, professional web sites with attractive, diverse and up-to-date information is still a difficult and expensive proposition. Many individuals and some companies and groups use web logs or blogs, which are largely used as easily updatable online diaries. Some commercial organizations encourage to communicate advice in their areas of specialization in the hope that visitors will be impressed by the expert knowledge and free information, and be attracted to the corporation as a result.

on popular web pages can be lucrative, and , which is the sale of products and services directly via the Web, continues to grow. Online advertising is a form of and advertising which uses the Internet to deliver marketing messages to consumers. It includes email marketing, (SEM), social media marketing, many types of (including advertising), and . In 2011, Internet advertising revenues in the United States surpassed those of and nearly exceeded those of .[80]:19 Many common online advertising practices are controversial and increasingly subject to regulation.

When the Web developed in the 1990s, a typical web page was stored in completed form on a web server, formatted in , complete for transmission to a web browser in response to a request. Over time, the process of creating and serving web pages has become dynamic, creating a flexible design, layout, and content. Websites are often created using software with, initially, very little content. Contributors to these systems, who may be paid staff, members of an organization or the public, fill underlying databases with content using editing pages designed for that purpose while casual visitors view and read this content in HTML form. There may or may not be editorial, approval and security systems built into the process of taking newly entered content and making it available to the target visitors.

Communication

is an important communications service available via the Internet. The concept of sending electronic text messages between parties, analogous to mailing letters or memos, predates the creation of the Internet. Pictures, documents, and other files are sent as . Email messages can be to multiple .

is a common communications service realized with the Internet. The name of the principle internetworking protocol, the , lends its name to (VoIP). The idea began in the early 1990s with -like voice applications for personal computers. VoIP systems now dominate many markets, and are as easy to use and as convenient as a traditional telephone. The benefit has been in substantial cost savings over traditional telephone calls, especially over long distances. , , and networks provide in customer premises[83] and inexpensive VoIP network adapters provide the connection for traditional analog telephone sets. The voice quality of VoIP often exceeds that of traditional calls. Remaining problems for VoIP include the situation that emergency services may not be universally available, and that devices rely on a local power supply, while older traditional phones are powered from the local loop, and typically operate during a power failure.