Adjustable falls under several categories;
Tilt Wheel
Developed by General Motors' Saginaw Steering Gear Division, the seven position Tilt Wheel was made available in several General Motors products in 1963. Originally a luxury option on cars, the tilt function helps to adjust the steering wheel by moving the wheel through an arc in an up and down motion. Tilt Steering Wheels rely upon a ratchet joint located in the steering column just below the steering wheel. By disengaging the ratchet lock, the wheel can be adjusted upward or downward while the steering column remains stationary below the joint. Some designs place the pivot slightly forward along the column, allowing for a fair amount of vertical movement of the steering wheel with little actual tilt, while other designs place the pivot almost inside the steering wheel, allowing adjustment of the angle of the steering wheel with almost no change it its height.
Telescope Wheel
Developed by General Motors Saginaw Steering Gear Division, the telescoping wheel can be adjusted to an infinite number of positions in a 3-inch range. The Tilt and Telescope steering wheel was introduced as an exclusive option on Cadillac automobiles in 1965.
Adjustable Steering Column
In contrast, an adjustable steering column allows steering wheel height to be adjusted with only a small, useful change in tilt. Most of these systems work with compression locks or electric motors instead of ratchet mechanisms; the latter may be capable of moving to a memorized position when a given driver uses the car, or of moving up and forward for entry or exit.