Essential daemons
Init (don’t play with it if you are not an expert).
- is the first process to start after boot and places the system in single user mode of spawns a shell to read the startup files
- you can re-start the system by sending SIGHUP to init.
cron
- runs commands at preset times
- accepts crontabs (schedule files) from both users and administrators
inetd
- is a daemon that manages other daemons
- only works with network daemons