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 particular website, the web browser retrieves the necessary content from a web server and then displays the resulting web page on the user's device.
A web browser is not the same thing as a search engine, though the two are often confused.[1][2] For a user, a search engine is just a website, such as Google Search, Bing, or DuckDuckGo, that stores searchable data about other websites. However, to connect to a website's server and display its web pages, a user must have a web browser installed.[3]
Web browsers are used on a range of devices, including desktops, laptops, tablets, and smartphones. In 2019, an estimated 4.3 billion people used a browser.[4] The most used browser is Google Chrome, with a 64% global market share on all devices, followed by Safari with 17%.
The first web browser, called WorldWideWeb, was created in 1990 by Sir Tim Berners-Lee.[6] He then recruited Nicola Pellow to write the Line Mode Browser, which displayed web pages on dumb terminals; it was released in 1991.[7]
Nicola Pellow and Tim Berners-Lee in their office at CERN.
Marc Andreessen, lead developer of Mosaic and Navigator
1993 was a landmark year with the release of Mosaic, credited as "the world's first popular browser".[8] 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.[8] 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.[9]
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.[10]
WorldWideWeb was the first web browser.[11]
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.[12]
Apple released its Safari browser in 2003. It remains the dominant browser on Apple platforms, though it did not become popular elsewhere.[12]
The last major entrant to the browser market was Google. Its Chrome browser, which debuted in 2008, steadily took market share from Internet Explorer and became the most popular browser in 2012.[13][14] Chrome has remained dominant ever since.
In terms of technology, browsers have greatly expanded their HTML, CSS, JavaScript, and multimedia capabilities since the 1990s. One reason has been to enable more sophisticated websites, such as web applications. Another factor is the significant increase of broadband connectivity, which enables people to access data-intensive web content, such as YouTube streaming, that was not possible during the era of dial-up modems.
