A direct link to a specific function or feature within a Web page
. While a browser bookmark takes you to a specific page, the bookmarklet will take you to a function, such as a specific search (including the search phrase) on a Web page
, a tagged location on Google maps and others. Bookmarklets are possible due to browser support of the protocol
See also “Roll Your Own Custom Bookmarklets In Firefox, part 2” on LinuxPlanet.