Web browsers are software applications that allow users interact with objects (e.g. text, images, videos) by retrieving, presenting, and traversing the information on a web page downloaded from the World Wide Web, a local area network, or other types of file systems. Web browsers also allow navigation between web pages (or websites). The primary purpose of a web browser is to retrieve information resources and to display the information to the user. When the user inputs a Uniform Resource Identifier (URI) into the browser, the browser will determine how the URI will be interpreted. For example, the http: in the URI / identifies the resource to be retrieved using 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. Prefixes that the web browser cannot handle are often passed to another application entirely. For example, mailto: URIs are usually passed to the user's default e-mail application, and news: URIs are passed to the user's default newsgroup reader. Web browsers are available with a range of features. Typically, most web browsers allow users to open multiple sources of information at a time. Early versions of Microsoft’s Internet Explorer allowed users to open multiple pages of information to be opened in different windows. The browser now allows for multiple pages to be opened in different tabs within the same window; this feature is also available when using Mozilla’s Firefox browser. Many web browsers also include pop-up blockers, which prevent unwanted windows from opening. Most browsers range in having minimal, text-based user interfaces with simple hypertext markup language (HTML) support to rich interfaces that support a wider variety of file formats and protocols.

Web Browser Interfaces

Typical web browser interfaces include back and forward buttons for easy browsing to previous resources; a refresh and reload button; a stop button for canceling the resource from loading; a home button to direct users to their homepage; and an address bar for inputting the URI of the desired resource.

Additional Features

Additional features for web browsers can include additional components such as e-mail support, Usenet news, and Internet Relay Chat (IRC); sometimes, browsers with such capabilities may be called “Internet suites” rather than browsers. Most web browsers can also be extended by using plug-ins, or downloadable components that provide additional features.