FTP is the Internet standard File Transfer Protocol that is used to send and receive files over the Internet . It runs over TCP and uses two separate ports for control and data connections between the client and server applications . Control port uses Port 21 which is used for sending control information such as username , password, put/get commands, etc while data files are usually transferred on port 20.
Modes of Running FTP:
FTP runs in two modes : Active and Passive