Well, if it’s wax and nothing but wax it’s the buffing off stage.
Most automotive ‘waxes’ contain both waxes and polishing compounds though, so the answer there would be “Both”. Rubbing it on briskly gives you the most polishing action, so your technique is sound.
Wax shines stuff by filling in the microscopic valleys. Polish shines stuff by knocking down the microscopic ridges.
Whatever you do, don’t use Johnson’s Floor Wax on your car.
When I was a lad, my friend’s mom ordered us to wax her Pacer. We found some wax in the garage and started rubbing it in. We applied it to the whole car, under the direct Florida sun, in little 8" circles, and then started buffing.
It didn’t buff.
That Pacer spent the rest of its life with 8" swirlie patterns all over it.