In the "linear" region, the Mosfet is a linear voltage-controlled resistor with fixed transconductance.
In the "saturation" region the Mosfet transconductance is not linear.
There are many articles about it in Google, here is one: **broken link removed**
As explained above, it's neither constant. Do you mean conductance for a fixed Vgs or fixed Id value?How is it constant in the saturation region and varies in the linear region.Please elaborate!