Several courses sold together at one price.
A bundle creates enrolments and steps aside
Buying a bundle creates an independent enrolment for each course in it. From then on the student's access comes from those enrolments, not from the bundle.
The practical consequence: remove a course from the bundle later and previous buyers keep their access. Add one and previous buyers do not get it.
A bundle's price is its own
The bundle price is set separately and is not derived from the sum of its courses. Changing a course's price does not change the bundle's.
Duplicate enrolments are not created
If the student is already enrolled in one of the bundle's courses, a second enrolment is not made for it.