Sort of correct, yes "the outer part (that the wheel bolts to) is the hub (has the bearing inside)"

I wouldn't say there is an inner part at all, the hub is the hub, it's one thing/piece. The rotor is a rotor, it bolts to the hub.
For the 5/10 lug.

The 8 lug is even simpler, the hub and rotor are cast as one piece, bearings are fit in it. In other words the hub/rotor is one single thing, nothing bolted together.

•1951 GMC 250 in the Project Journals
•1948 Chevrolet 6400 - Detroit Diesel 4-53T - Roadranger 10 speed overdrive - 4 wheel disc brakes
•1952 Chevrolet 3800 pickup
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"First, get a clear notion of what you desire to accomplish, and then in all probability you will succeed in doing it..." -Henry Maudslay-