What is FTP and how does it work?

FTP stands for File Transfer Protocol. It is the standard Internet protocol for transferring files from one computer to another. FTP is part of the TCP/IP protocol suite. TCP/IP is the basic protocol that runs the whole Internet. Whether you are checking your email, visiting a web site or downloading files, you are using TCP/IP. There are a number of smaller protocols that run on top of TCP/IP, such as email, HTTP, and Telnet. FTP is one of these. Its sole function is to move a file from a server to a client (download) or from a client to a server (upload).

FTP requires two computers, one running an FTP server, the other running an FTP client. The exchange is initiated by the client which logs in under an accepted user name and password. Once this occurs, a session is opened and stays open until closed by either the client or the server, or until it times out. While the session is open, the client may execute numerous FTP commands on the server. These include commands to change directories, list files, get files and put files.