Rack and pinion steering: It's the sort of terminology that seems more in keeping with a chiropractor than mechanic, but rack and pinion steering is firmly in the realm of the mechanic and engineer.
In this system, the steering shaft has a small gear at its base. This meshes with a toothed bar connected to the steering linkage that controls the two front wheels.
The pinion engages a bar with a row of teeth cut along one edge. When the steering wheel is turned, the pinion turns and moves the rack from left to right.
This movement is carried through tie rods to the steering arms at the wheels. And so the car turns the corner.