Originally Posted by Agent 488

Every web browser stores a cache of the websites you visit (e.g. HTML pages, images) to reduce bandwidth usage and server load. This is called the browser's cache. Clearing it occasionally can free up space on your computers hard drive if it's running low. Since every browser is different, the following sections will outline the steps involved in clearing the cache for several popular web browsers. February 27th is National Clear your Browser's Cache day; although you should do it more than once per year.