"Apple butter?" Winston said, picking over the assorted vials of jams. "Where's strawberry?"
Apple butter has, of course, no butter. It's buttery, though, from the smoothness achieved from a slow reduction of the pulp and juices, the way a caramel is smooth (though not that smooth).
Apple butter will last on a shelf longer than applesauce. The former also packs more flavor than the latter. Apple butter is kind of like apple roux.
Apple butter tastes good, on toast, with butter.