Field-Effect Transistors (FETs) are semiconductor devices that control electrical current using an electric field rather than current at a control terminal, making them voltage-controlled devices. FETs are widely used for amplification, switching, and signal modulation in both analog and digital circuits.
They are commonly found in amplifiers, voltage-controlled resistors, RF circuits, digital logic circuits, power management systems, and switching applications, where high input impedance and low power consumption are important. FETs are available in several types, including Junction FETs (JFETs) and Metal-Oxide-Semiconductor FETs (MOSFETs), each suited for specific applications.