A Field-Effect Transistor (FET) is a type of transistor that controls the flow of electrical current using an electric field. It has three main terminals: the source, gate, and drain. The gate terminal regulates the current between the source and drain, allowing for efficient switching and amplification of signals. FETs are widely used in electronic devices due to their high input impedance and low power consumption. There are several types of FETs, including JFET (Junction FET) and MOSFET (Metal-Oxide-Semiconductor FET). Each type has unique characteristics that make them suitable for different applications, such as amplifiers, switches, and digital circuits. FETs play a crucial role in modern electronics, enabling the development of various technologies.