The standard method for downloading and uploading files over the Internet. With FTP, you can login to a server and transfer files (meaning you can "send" or "receive" files). Some sites have public file archives that you can access by using FTP with the account name "anonymous" and your e-mail address as the password. This type of access is called anonymous FTP. Macintosh owners use a program called Fetch; one of the best FTP programs for Windows is called WS-FTP. Knowing FTP is necessary (and easy) if you want to create your own Web site.
Note: You may also hear this noun used as a verb. For example, "I just finished FTP'ing the last of the files." Or, "I FTP'ed the new images to the site last night."