A MOSFET, or Metal-Oxide-Semiconductor Field-Effect Transistor, is a type of transistor used to amplify or switch electronic signals. It consists of three main terminals: the gate, drain, and source. The gate controls the flow of current between the drain and source, allowing for efficient signal modulation in various electronic devices. MOSFETs are widely used in digital circuits, power electronics, and amplifiers due to their high efficiency and fast switching capabilities. They are essential components in many modern technologies, including computers, smartphones, and renewable energy systems, enabling better performance and energy management.