Favicon
A favicon (pronounced /ˈfævɪˌkɒn/; short for favorites icon), also known as a shortcut icon, website icon, URL icon, or bookmark icon is a file containing one or more small icons, most commonly 16×16 pixels, associated with a particular website or single web page.
Browsers that provide favicon support typically display a page’s favicon in the browser’s address bar and next to the page’s name in a list of bookmarks.
Browsers that support a tabbed document interface typically show a page’s favicon next to the page’s title on the tab, and site-specific browsers use the favicon as desktop icon.