Gate terminal - field-effect transistor:

The names of the terminals consider to their functions. The gate terminal might be thought of since controlling the opening and closing of a physical gate. This gate allows electrons to flow via or blocks their passage through creating or eliminating a channel in between the source and drain. Electrons flow from the source terminal in the direction of the drain terminal if affected by an applied voltage. The body just refers to the bulk of the semiconductor where the gate, source and drain lie. Generally the body terminal is connected to the highest or lowest voltage in the circuit, depending upon type. The body terminal and the source terminal are occasionally connected together as the source is as well sometimes connected to the highest or lowest voltage within the circuit, though there are various uses of FETs which do not have such type of a configuration, like transmission gates and cascode circuits.