Starter Motor, (Exchange).
A device, power by electricity, pneumatic, or hydraulics, used to rotate / crank a vehicle's engine as to initiate the engine's operation under its own power.

STARTER MOTOR, EXC

Starter Motor
You turn the key, hear a loud sharp CLICK, and your engine doesn't crank—sounds like your Volvo may need its starter replaced. If any of these symptoms sound familiar, contact our service department.