Originally, a hand crank was used to start engines, but it was inconvenient, difficult,
and dangerous to crank-start an engine.
So in the early 1900’s the starter motor was developed.
A starter motor (also starting motor, or starter) is an electric
motor that rotates an internal-combustion engine so as to initiate the engine's operation under its own power.
When current from the starting battery is applied to the solenoid, usually through a key-operated switch, the solenoid engages a lever that pushes out the drive pinion on the starter driveshaft and meshes the pinion with the starter ring gear on the flywheel of