eli5: What (if any) is the difference between an engine and a motor?

Question

I’ve heard these words used interchangeably over the years, with engine being more prevalent. Is there any difference? Why is a small gas-driven device like a lawnmower commonly said to have a motor, while what is under the hood of a car is almost always referred to as an engine?

In: 160

Answer 1

Rocket guy here.

A motor is a solid-propellant device that can’t be shut off once started. An engine uses liquid fuel and has throttle controls.