What happens when your Core Data models version are no longer compatible with each other? Well, you'll have to resolve this inconsistencies through <b>Custom Migration Policies</b>. This is quite difficult and can be resolved in several ways. In today's video, we'll look at using a <b>Mapping Model</b> as well as <b>NSEntityMigrationPolicy</b>. I hope these examples will be helpful in correctly guiding you through this rough concept.