I had an old battery operated motor for my 5" Newtonian I had years ago. You do the alignment, then the motor swings the scope at the speed the earth rotates, keeping the stars aligned for you... or planet... or nebula...
I now have a more modern Alt/Az scope, that the two motors built in, and can track pretty much anything. But in Alt/Az mode you will get "twisting" of the stars. Add a wedge and go to polar mode and the one motor does the same job as on my old Newt.
So yes... the motor is used for tracking an object.
