4.1.2.3. Daemons
Daemons are server processes that run continuously. Most of the
time, they are initialized at system startup and then wait in the
background until their service is required. A typical example is
the networking daemon, xinetd, which is started in almost
every boot procedure. After the system is booted, the network
daemon just sits and waits until a client program, such as an FTP
client, needs to connect.