A shortening of favorite icon. It generally refers to a 16 by 16 pixel image (although additional sizes are supported) associated with an website which appears in the browser address bar when the site is visited. It may also appear next to the page listing in the browser’s bookmark and history listings.
Favicons were introduced by Microsoft in 1995 with the release of Internet Explorer 5 and adopted as a recommendation (standard) by the W3C in 1999.
Modern browsers check for the presence of a favicon in the root folder of a website although a different location can be specified by including a link tag in the <head> of a document in the following format:
<link rel="shortcut icon" href="http://example.com/myicon.ico" />
Note: Since all modern browsers check for the presence of a favicon, its absence will generate 404 errors in the site’s error log.