When is the MOSFET used as an amplifier?

Is it when it is in the Ohmic Region or the Saturation or is it not used at all?
This is not an answer for HW or a test dw, it is a question that I found today in my textbook and I wasn't sure of the answer.
I think it is Saturation, since in ohmic region it is used as a Resistor...

A mosfet operates in the saturation region when amplifing.

( many will argue this; but they are confused with BJT saturation operation )

Saturation region it is.

Yeah, you have to readjust your thinking of the mosfet as an amplfier, I still haven't gotten into that, my typical usage of a FET is for switching or variable resistors, but I an opamp takes care of the gate feedback for that, haven't needed to run one as a power amp before.