Jake brakes?

What is the difference between jake breaking and engine braking?

A Jake Brake is a feature on large diesel engines to increase compression braking. Jake brakes can be turned on by the operator when additional engine or compression braking is desired.

Jake brakes are rather noisy. This is why Jake brakes are banned in many populated areas. A truck driving friend of mine didn't realize a motorcycle cop was driving right beside him when he turned on his Jake brakes. The loud engine noise scared the wit out of the cop beside him who pulled him over assuming that my friend did it intentionally to rattle the cop.