Any part of the steering system on a car, be it rack-and-pinion, power or not, includes tie-rods, knuckles, steering column coupler, ball joints. Modern cars have electric steering, but still need couplings and knuckles.
A cars driveshaft, a cars steering column, a socket set,
There are no grease fittings on the new cars as the ball joints and steering assembly is maintenance free.
there are no grease fittings on the newer cars, all ball joints and steering parts are permanitly sealed.
Normally there are constant velocity joints not u-joints.
This depends on what car we are talking about. Some now rare and now very old cars had a system that did this. The steering was terrible! Other-wise the steering now pivots on several types of ball joints, king pins and bearing depending on make and model.
Only if it has power steering. Most all cars these days do.
the steering wheel
Power assisted steering.
yes.
Chrysler came out with power steering in 1951
If the steering wheel spins freely but the wheels don't turn, the steering shaft (which runs from the steering wheel, into the engine compartment, and down to the steering box) probably came apart. Usually there are one or more joints in the steering shaft, to allow it to angle around obstructions in the engine compartment. It may be that the shaft separated from one of these joints. Find the steering shaft in the engine compartment and see if it's continuous all the way down to the steering box. Also see if when you turn the steering wheel, if the shaft turns also. If it doesn't, then there's a problem with the steering wheel's mounting to the shaft. At the steering wheel, the shaft is usually cut with a bunch of little notches, which the steering wheel hub slides onto. If these notches have gotten stripped, then the hub has nothing to grip, and the wheel will spin free without moving the steering shaft.