What is the MOSFET: Basics, Working Principle and Applications

The MOSFET (Metal Oxide Semiconductor Field Effect Transistor) transistor is a semiconductor device which is widely used for switching and amplifying electronic signals in the electronic devices.  The MOSFET is a core of integrated circuit and it can be designed and fabricated in a single chip because of these very small sizes.  
The MOSFET is a four terminal device with source(S), gate (G), drain (D) and body (B) terminals. The body of the MOSFET is frequently connected to the source terminal so making it a three terminal device like field effect transistor. The MOSFET is very far the most
common transistor and can be used in both analog and digital circuits.
The MOSFET works by electronically varying the width of a channel along which charge carriers flow (electrons or holes).
The charge carriers enter the channel at source and exit via the drain. The width of the channel is controlled by the voltage on an electrode is called gate which is located between source and drain. It is insulated from the channel near an extremely thin layer of metal oxide. The MOS capacity present in the device is the main part.