What is the Difference Between the Expires and Last Day to Register drop-down lists on the Registration screen for a LearnTrack?

The Last Day to Register drop-down lists allow you to specify the very last day when a learner can register or be registered in the LearnTrack. Typically, this date would occur before the start of the LearnTrack. Also, this selection is required.

The Expires drop-down lists allow you to specify when the LearnTrack is scheduled to end. This selection is optional.