“It’s OK to leave this relationship as a to-one relationship. A dog can have many walks, but a walk can only belong to one dog — for the purposes of this app, at least.
The inverse lets the model know how to find its way back, so to speak. Given a walk record, you can follow the relationship to the dog. Thanks to the inverse, the model knows to follow the walks relationship to get back to the walk record.
This is a good time to let you know the data model editor has another view style. This entire time you’ve been looking at the table editor style. Toggle the segmented control on the bottom-right to switch to the graph editor style:”