ProFTPd is the name of the preinstalled application that powers your FTP services. ProFTPd is an FTP server application written for UNIX and similar in design and concept to the Apache Web server. Among other things, ProFTPd supports resumable downloads – a feature that allows those visitors whose FTP client supports it, to pick up where they left off in the event they get disconnected during a file transfer.
ProFTPd is spawned by the Xinetd application whenever someone attempts to connect to your server through FTP. If desired, FTP services can be disabled using the inetctl command, as discussed in the Controlling Xinetd section of this guide.