A reenterable load module does not modify itself. Only one copy of the load module is loaded to satisfy the requirements of any number of tasks in a job step. This means that even though there are several tasks in the job step and each task concurrently uses the load module, the only central storage needed is an area large enough to hold one copy of the load module (plus a few bytes for control blocks). The same amount of central storage would be needed if the load module were serially reusable; however, the load module could not be used by more than one task at a time.