Web browser

From ArticleWorld


A web browser is a computer program used to display and interact with content on private HTTP servers and the World Wide Web network. It is normally able to deal with text and images, and supports hyperlinks. Web browsers are the most common HTTP user agents, and allow quick and easy access to the World Wide Web. The most popular browsers are Mozilla Firefox, Opera, Safari, Internet Explorer and Netscape.

Standards and protocols

Web browsers are the clients of so-called web servers, generally using the HTTP protocol. Although some browsers do support other protocols as well (like FTP), HTTP is the standard protocol of the WWW. HTTP/1.1 is the most widely used version at the moment, despite the fact that not all web browsers comply with all of its requirements (the most notable one being Internet Explorer).

In order for web pages to be located, web browsers use a Uniform Resource Locator (URL) which is based on the address paradigm. The standard file format is HTML, which is delivered in plain-text format, although web browsers also support displaying other file formats like some image files.

When providing additional services (like e-mail client functions or IRC chat), web browsers also implement the protocols required by these services.

Features

The World Wide Web is the host of many important technologies, often requiring support for several standards. The most important features of web browsers include:

  • Basic web browsers support: bookmarks, content caching, various media types. Many of the media types are proprietary and require plugins, so plugin support is also important.
  • Standards: HTTP, HTTPS, (X)HTML and XML support. Graphic support for the most common images, including PNG, JPEG, SVG and GIF. CSS support is also important at the moment, along with JavaScript and DHTML. Cookie support is important for some web sites.
  • Usability: autocompletion of URLs and support for history. Optional tab browsing and screen reader/full speech support for visually impaired users. Pop-up advert blockers and anti-phishing supports are important.