A lock Cylinder is when a car can be locked or unlocked by operating a mechanical mechanism.

In most cars,  the ignition key is placed in the ignition lock or lock cylinder in the steering column,

• The ignition switch may attach to the lock or mount farther down the steering column,
• Turning the ignition key moves an actuator rod that operates the ignition switch.
• The five positions of ignition lock are: accessory, lock, off, run, and start.