Explanation of the acronym  

MOSFETs are a type of transistor. ‘Metal Oxide’ refers to the fact that it consists of a metal conductor, ‘Silicon’ states the material of the semiconducting layer, and ‘Field Effect’ refers to how the current flowing through the semiconductor is controlled.

Operation 

An electric field places a charge onto the gate of the MOSFET, this controls the the amount of current flowing through the semiconductor. Current flows from the drain terminal to the source terminal.