Rocket Engine or Rocket Motor?

According to the book there is a difference. I didn't know it before, did you?

A rocket motor contains all its propellant already in the combustion chamber before ignition.

A rocket engine holds at least some of it in another place and injects it into the combustion chamber when it is needed. That can be the fuel or the oxidiser or both. So these micro-hybrids must be rocket engines.