…and that makes for an actor. Took myself a little while to figure it out, but actor is exactly what you used to see in prefabs. Create one by creating “blueprint” of a type of actor, or a code class of a type of actor.
Originally I thought it was too, but no, these are not quite the same. BPs are not correct prefabs, as they only store the top level public properties of an actor and totally ignore data stored in attached UComponent objects. You cannot snapshot editor data in, say, a SplineComponent back to the originating BP asset, even though is is totally possible with a binary copy operation like “Create composite BP”.