Brushless setups for cars and trucks

Great List Jagboy! Especially for a new guy. Can you take a minute and anwer a couple futher questions on set up-
How do you match controller, batteries and motor using those numbers?
What mechanically does "turns" mean? (I realize a 8 turn is faster on fewer cells than a 10, but why)
Those two answers would make everything I am reading clear! Thanks!