inetd(8) “super-server” handles incoming network requests for network services that aren’t used very often. After all, many systems don’t have a steady stream of incoming FTP requests, so why have an FTP daemon running constantly? Instead,
inetd listens for incoming network requests, and when an FTP request arrives, it starts the FTP server and feeds it the request. Other common services that frequently (but not always) run through
inetd include ident, finger, and TFTP. Many of these services can also run standalone, if the application usage warrants it.
inetd also handles functions so small and rarely used that they’re easier to implement within
inetd itself, rather than by calling a separate program. These ...