A
MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) is an
active component.
Active components are devices that can amplify signals or control current flow. MOSFETs are considered active because they can amplify electrical signals and control the flow of current between two terminals (drain and source) by applying a voltage to the third terminal (gate). This allows MOSFETs to be used in a variety of applications, such as in amplifiers, switches, and digital logic circuits.
In short,
MOSFETs are active components because they can control the flow of current based on an external input.