The steering wheel and column has 4 primary functions:
Vehicle Steering
The steering wheel is the first link between the driver and the vehicle.
The steering wheel is fastened to a steering shaft within the column. At the
  lower end of the column, the intermediate shaft connects the column to the
  steering gear.
Vehicle Security (Some Vehicle Models)
Theft deterrent components are mounted and designed into the steering
column. The following components allow the column to be locked in order to
  minimize theft:
|     •  | The steering column lock (manual transmission only) | 
 
Driver Convenience
The steering wheel and column may also have driver controls attached
for convenience and comfort. The following controls may be mounted on or near
  the steering wheel or column.
|     •  | The headlamp dimmer switch | 
 
|     •  | The wiper/washer switch | 
 
|     •  | The horn pad/cruise control switch | 
 
|     •  | The redundant radio/entertainment system controls | 
 
|     •  | The tilt or tilt/telescoping functions | 
 
|     •  | The navigation/OnStar® features | 
 
Driver Safety
The energy-absorbing steering column compresses  in the event of a front-end
collision, which reduces the chance of injury  to the driver. The mounting
 capsules break away from the mounting bracket in the event of an accident.