File with a .JOB extension contains data regarding Windows task schedule – its name, elements describing release of a task and its conditions and also actions performed. Task may comprise of initialising an application, displaying a message or sending an email. The conditions in which a given task can be performed can be defined, for instance: only while low battery or system inactivity.

JOB files are used by a system application in order to plan automatically performed tasks (Task Scheduler). Such actions as system or software updates availability verification , initialising antivirus scan are usually performed as serial tasks. Tasks can be also initialised manually, however, they are usually performed according to a specific schedule.