A transistor is a basic semiconductor element that consists of three terminals and three series-connected areas with different doping that determines the transition of the transistor (PNP or NPN). Its main task is amplification, switching and conversion of electrical signals and part of all modern electrical devices.
The JFET field effect transistor is one of the most common transistors. The name JFET comes from Junction Field - Effect Transistor. Its main application is as an electrical switch, resistor or as an amplifier. Unlike bipolar transistors, the JFET is voltage controlled. JFET transistors can be P or N junction, so if the voltage to the gate is negative the current will be reduced, and vice versa if it is positive. A JFET has a large input impedance and a small current. Unlike the other type of MOSFET, the JFET has a direct connection between the channel and the gate, and the JFET can operate at lower currents.