Tricky one, answering questions - you never know what the other person knows already. But given that these forums are also read by people looking to learn, I tend to err on the side of giving a bit too much rather than too little info. So, nothing personal intended!

"motor controller" is definitely wrong, though, as this implies something that directly connects to a motor which the motion controller does not. Might also be interpreted as something like a DC spindle motor controller which is a very different animal. Good luck with the project - lots of fun!