I understand the maths mostly. But what are the practical uses of operating in Triode or Saturation? what are some examples of why you use one region as opposed to another

 

Describe, preferably in words, the voltage-current relationship in the two regions and how they differ. Looking at the plots of the drain current versus the gate-source voltage and also the drain current versus the drain-source voltage might help.

 

The current increases linearly inthe triode region as the D-S voltage increases. In saturation it remains near constant.
So in saturation the mosfet 'eats up' the extra power to provde a constant current. acts as a voltage controlled resistor?
In triode its more like a switch, the mosfet can drop virtually no power?

yea?
so what are the practical advantages of either region. (like people use triode for switching on an LED or use in saturation for something, amplifier?)