Inventory policies and tasks let you configure the inventory configuration options that you want to run on target computers. When you want to gather inventory only once or immediately, you use inventory tasks. When you want to gather inventory on a recurring schedule, you use inventory policies.
When you schedule an inventory policy, it runs on the schedule irrespective of whether any maintenance window is open. When you schedule an inventory task on a set of computers and do not select the Override Maintenance Window option, and the same set of computers has a maintenance window enabled, the task waits for the maintenance window to open.