You can also have more tasks in one job. This is especially useful when you have for example three network controller and one should always run but you want to update and reboot them. For such a case you can have task number 1 update and reboot controller 1 and only until this is finished the job starts task 2 where you update and reboot controller 2 and 3. You can set the time every task is allowed to take and also the maximum length the job in general can take.