Web browsers uses the hard disk to store Web pages (including the page itself and anything that makes up the pages, such as images), putting them into a special folder on your disk (this folder is the �cache�). The first time you ask for a Web page, your browser goes to the web server on the Internet, gets the page and all of its components, renders it for you to view and stores a copy of it in this cache folder. The next time you request access to this page, your browser (depending on controls explained later) checks if the date of the page on the Internet is newer than the one in the cache folder. If the date of the page on the Internet is older than the one stored on your haddrive (the cache), your browser uses the one on your harddrive instead of downloading it from Internet.
A Moment's insight is sometimes worth a Life's experience.