Listeners are a combination of an IP address and port number on which a server is configured to allow connections. You can configure as many listeners as you want, up to one per port on each available IP address.
There are two kinds of listeners: FTP and SSH. FTP listeners provide access to hosts using basic FTP and SSL (implicit and explicit). SSH listeners provide access to hosts using the SFTP protocol over SSH.
By default, WS_FTP Server creates three listeners: