The MOSFET is a particular type of Field-Effect Transistor (FET) where the output current flowing between the source and drain terminals is controlled by a variable electric field applied to the gate terminal. The gate design determines the type of FET. In the MOSFET, the gate is insulated from the channel by a very thin (typically less than the wavelength of light) layer of glass. This means the MOSFET has practically infinite impedance, which makes it useful for power amplifiers. They can also be found in some integrated circuits (IC) and often used in wireless microphone receivers.
(See FET)