What are Active and Passive FTP modes?
There are two types of transfer modes for the File Transfer Protocol (FTP). At Active Mode transfers, the client listens for the incoming data connection, and in Passive Mode transfers, the servers listens for the incoming data connection. In case of active connections (where the server connects to the client to transfer data), the server binds on port 20 before connecting to the client. For passive connections, there is no such restriction.