As you browse the web, Firefox helpfully remembers lots of information for you -- sites you've visited, files you've downloaded and more. All of this information is called your history. However, if you are using a public computer or share a computer with someone, you may not want others to be able to see these kinds of things. This video will how you how to delete this info. More - http://support.mozilla.org/kb/remove-recent-browsing-search-and-download-history