A web browser (commonly referred to as a browser) is a software application for accessing information on the World Wide Web. When a user requests a web page from a particular website, the web browser retrieves the necessary content from a web server and then displays the page on the user's device.
A web browser is not the same thing as a search engine, though the two are often confused. For a user, a search engine is just a website that provides hyperlink to other websites. However, to connect to a website's server and display its web pages, a user must have a web browser installed.
Web browsers are used on a range of devices, including desktop computer, , tablet computer, and . In 2019, an estimated 4.3 billion people used a browser. The most used browser is Google Chrome, with a 64% global market share on all devices, followed by Safari with 18%. Other notable browsers include Firefox and Microsoft Edge.
1993 was a landmark year with the release of Mosaic, credited as "the world's first popular browser". Its innovative graphical interface made the World Wide Web system easy to use and thus more accessible to the average person. This, in turn, sparked the Internet boom of the 1990s, when the Web grew at a very rapid rate. Marc Andreessen, the leader of the Mosaic team, soon started his own company, Netscape, which released the Mosaic-influenced Netscape Navigator in 1994. Navigator quickly became the most popular browser.
Microsoft debuted Internet Explorer in 1995, leading to a browser war with Netscape. Microsoft was able to gain a dominant position for two reasons: it bundled Internet Explorer with its popular Microsoft Windows operating system and did so as freeware with no restrictions on usage. Eventually the market share of Internet Explorer peaked at over 95% in 2002.
In 1998, Netscape launched what would become the Mozilla Foundation to create a new browser using the open source software model. This work evolved into Firefox, first released by Mozilla in 2004. Firefox reached a 28% market share in 2011. Apple released its Safari browser in 2003. It remains the dominant browser on Apple platforms, though it did not become popular elsewhere.
In 2011, the first version of HTTPS Everywhere was launched, while NoScript got its main awards and Mozilla launched the stable version of Tor Firefox browser, the free doodle to navigate the dark web.
Microsoft released its Microsoft Edge browser in 2015 as part of the Windows 10 release, and rebuilt it as a Chromium-based browser in 2019. (Internet Explorer is still used on older versions of Windows.)
This process begins when the user inputs a URL (URL), such as <nowiki></nowiki>, into the browser. Virtually all URLs on the Web start with either http: or https: which means the browser will retrieve them with the Hypertext Transfer Protocol (HTTP). In the case of https:, the communication between the browser and the web server is HTTPS for the purposes of security and privacy.
Web pages usually contain to other pages and resources. Each link contains a URL, and when it is clicked or touchscreen, the browser navigates to the new resource. Thus the process of bringing content to the user begins again.
Most browsers use an internal cache of web page resources to improve loading times for subsequent visits to the same page. The cache can store many items, such as large images, so they do not need to be downloaded from the server again. Cached items are usually only stored for as long as the web server stipulates in its HTTP response messages.
The menu has different types of settings. For example, users can change their home page and default search engine. They also can change default web page colors and . Various network connectivity and privacy settings are also usually available.
Most browsers have these user interface features:
There are also niche browsers with distinct features. One example is text-only browsers that can benefit people with slow Internet connections or those with visual impairments.