MOSFET is a type of transistor used for switching electronic signals and amplification. It has three terminals - the source, gate, and drain. MOSFET construction involves depositing an oxide insulating layer on a substrate, to which a gate terminal is connected. There are two types - P-type and N-type MOSFETs - depending on whether the substrate is P-doped or N-doped. MOSFETs can operate in depletion or enhancement mode. In depletion mode, a negative gate voltage depletes carriers and reduces current flow, while in enhancement mode a positive gate voltage enhances carrier flow and increases current. Common applications of MOSFETs include radiofrequency amplifiers, passive circuit elements, motor