FTP (File Transfer Protocol) is simply used for transfering files accross the internet.
Although files can be downloaded from your web browser it is far more effective to use an 'FTP Client' (or progam) especially if you are transfering files in quantity or frequently. FTP programs handle the transfer of files to and from your PC and servers on the internet far quicker and more efficiently. A common use for FTP progams is for maintaining web sites.

This page provides links to many FTP programs used for transferring files from your local PC to servers on the internet.

read more about ftp at FTPplanet.com