Enrollments

Every record of "who enrolled in which plan of which course".

The enrollment list — source, plan, access status and expiry

How this differs from orders

Orders record money. Enrollments record access.

One order can unlock several courses (a bundle purchase), and a manual grant creates an enrollment with no order at all. When you need to check someone's access, look here.

Question: Can an enrollment have an expiry date?

Yes. Set a viewing period on the plan (180 days, say), and access closes automatically when it runs out.