No problem, I'll jus show you pictures

Gives me something to do.

this is an ESC (Electronic Speed Control). They control throttle/brake/reverse etc etc
The COM i cant find a picture of, but it is what the brushes connect to to create an electrical current.

these are brushes, and are used in rebuildable stock/modified motors. They can alter the performance of your engine to either give you longer run times, faster excelleration, or faster top end speed.
jus a few things