The term daemon comes from ancient Greek mythology. There, the Daemons were half-gods, acting as messengers between the people on earth and the gods. This FTP server acts, likewise, as a messenger for file transfer between FTP clients and your computer. Once started it sits in the background waiting for a client to contact it and after communications are established, acting out the client's commands.
出自On-line help for Serv-U v2.5