There are two types of FTP, passive and active. Your FTP connection will be either one or the other, but not both.

FTP uses 2 connections to accomplish file transfer.
1) A command connection
2) A data connection

A command connection is always established. If you are using passive FTP, then the FTP server will host the server connection for the data connection.

If you are using active FTP. Then your local computer will host the server for the data connection.

Depending on your firewall settings, and your server's firewall settings, you may want to use either passive or active FTP.