Difference between Subscriptions & License?

Problem/Motivation

Trying to setup a membership section on our site where user pays and is given a different role (to access content).
This should be subscription based where their role expires after a month or after a year (depending if they selected monthly or yearly).

I tried to follow the documentation but it does not mention the difference between a subscription and a license.
Can someone please explain the difference?

In my product variation (called subscriptions), do I need to check the "Allow subscriptions" or the "Provides a license" option?

- It makes sense to select the "Allow subscriptions" since that will kick in the billing schedule, but does not seem to have a role option to make the user a member of a new role.

- It also makes sense to click the "Provides a license" option since that does have the role option, but it does not seem to have the billing schedule part.

- With these two differences it makes sense to click on both, but when I do select both, I get a license error and my site breaks completely and have to use a database backup to get it back where it was.

So how can I achieve the functionality I need? What is the difference between a subscription and a license?

Can these two be selected in the same product variation? Or if they should not be selected together, how can I achieve the membership functionality I need?

Thank you.