This article is from the Model Rockets FAQ, by Wolfram von Kiparski with numerous contributions by others.
I don't know. I don't really care. And neither should you! In this
document 'motor' and 'engine' are taken to mean the same thing and both
refer to "the thing in the rocket which makes it go 'whoosh!!' (or 'roar',
if flying high power :-)". If you want a sure way to start a fight with
a fellow rocketeer, just argue that whatever term he/she uses is the wrong