General   (General discussion, talk about anything.)

What do you want to know?

They function in a similar way to junction transistors, but the 'gate' connection which replaces the 'base' connection yields a very high impedance input, as control is not achieved by current flow, but varying the electrical field to modulate the charge carriers available between source and drain, therefore controlling the current in the S to D path.

Enhancement and depletion modes of control are used, but it is common for both to be used, complementary, which gives you the more complex devices such as the CMOS range of ICs.

I'm sure Google will find some nice illustrated accounts of FET operation.