What is FTP?

FTP stands for File Transfer Protocol. FTP is the standard method through which files are transmitted or sent from one computer to another using TCP/IP networks. (This includes the Internet.)

An 8-bit client-server protocol, FTP basically allows computer users to transfer a file or set of files remotely from their computer to another computer. An Internet connection is of course required, and a broadband Internet connection is recommended, especially if transmitting a large quantity of files or a few large files. FTP users can both upload files to a remote location or choose to download files from a remote location. In order to safeguard an FTP system from anonymous uploads and downloads, logins and passwords are generally used.

How FTP Works

As previously stated, FTP is only functional through TCP/IP networks. Although a file transfer protocol, FTP does not actually function as a medium through which files are transferred. Copies of files are made and the copy is transmitted through the FTP server.

Originally designed for peer-to-peer data transfers, FTP software connects your local host machine to the FTP software on the computer that you’re exchanging files with. FTP ports serve the purpose of establishing a connection between your computer and a remote computer and then transferring the selected files between the two.

FTP Ports

FTP is generally run on one of two ports, those being ports 20 and 21:

Port 20: A data stream (series of digitally encoded signals) that serves the purpose of ferrying data between the client and the server.

Port 21: A control stream through which the FTP server reads any/all commands.

One common problem associated with the dual ports relates to the transfer of large packets of data. While Port 20 is actively transmitting the data, Port 21 sits idly. As a result, the operation will occasionally time out, causing an interruption in the data transfer. If you connect to the Internet via a high speed broadband connection, this problem should not present itself too often.

FTP and Internet Browsers

Web hosts commonly use FTP to upload their Web files to the Internet. Because of its relation to Internet usage, FTP users no longer require the FTP software to be built in to their system. (Common FTP software types include Cute FTP and Smart FTP) FTP is now compatible with many Internet browsers such as the commonly used Internet Explorer. Browsers can connect with FTP servers by inserting the FTP login, password and address into the URL window. (ftp://<login>:<password>@<ftpserveraddress>) Files are then dragged and placed in the opened FTP browser window in the same manner that you would transfer a file locally. This process can be much simpler for people who are unfamiliar with FTP software / technology.