JFET

The junction gate field-effect transistor (JFET or JUGFET) is the simplest type of field effect transistor. Like other transistors, it can be used as an electronically-controlled switch. It is also used as a voltage-controlled resistance. An electric current flows from one connection, called the source, to a second connection, called the drain. A third connection, the gate, determines how much current flows. By applying an increasing negative (for an n-channel JFET) bias voltage to the gate, the current flow from source to drain can be impeded by pinching off the channel, in effect switching off the transistor.
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Junction Field Effect Transistor

Junction Field Effect Transistor, a type of Transistor where Conduction is controlled by modulating the width of a Depletion Region.

JUNCTION FIELD EFFECT TRANSISTOR. JFET