The scheduled tasks area is where you can select a variety of tasks to be scheduled. This includes server backups, start / stop / restart the server, or even send a server command such as an announcement. These are typed directly into the server console on the back-end, so it will appear to the server as though you are typing in the commands yourself.
Schedule options are every X minute and x hour. You can also say every X day, or a specific day. On the days you can also set a time so you can do something like: Backup every Tuesday at 3am. You could also schedule something along the lines of Restart Every Thursday at 4pm, or perhaps even
say Crafty is awesome every hour.