Strings of text that are links to other pages are called hyperlinks . Pages are viewed in a program called browser . Browsers fetch the page requested without any help from the user, interprets the text and formatting commands, and displays the page on the screen. When hypertext pages are mixed with other media, the result is called hypermedia . Browsers that cannot display hypermedia check the configuration file to determine how to handle the file using external viewers or helper applications .
Some browsers use the local disk to cache pages that they have fetched.
Before a page is fetched, a check is made to see if it is in the local cache. If so, it is only necessary to check of the page is still up to date. If so, the page need not be loaded again. To host a web browser, a machine must be directly on the internet. The browser establishes a TCP connection to the machine where the page is and then sends a message over the connection asking for the page.