What is the purpose of renewal fields on licences?

Summary:

We would like to start using licences and certifications on the talent profile to capture a number of licences which staff are required to renew on a regular basis.

When creating the list of licences, I had assumed the renewal fields related to the length of time the licence is valid for. However, when I add this particular licence to an employees talent profile it doesn't populate the expiry date or even the renewal required field.

I've seen from other posts that Oracle won't auto-populate the expiry date. I just wondered what the purpose of these fields are and if it matters if we complete them or not?