motor types

Okay, now I'm stymied.
I've got the steppers for the pasma machine,
but wa looking around for motors for the mill.

Cna someone explain what teh difference between "brushed dc",
"brushless dc", and "servo" are?
I know the difference in construction for brushed and brushless,
but what's optimum for our purposes?
Is one just a normal electric motor like those that run my machines?

Too much brain expansion for one week...

Weyland