An electrical transformer is a device that changes the voltage of alternating current (AC) electricity. It consists of two or more coils of wire, known as windings, wrapped around a core made of magnetic material. When electricity flows through one winding, it creates a magnetic field that induces a voltage in the other winding, allowing for the transfer of electrical energy between circuits. Transformers are essential in the power distribution system, enabling electricity to be transmitted over long distances efficiently. By stepping up the voltage for transmission and stepping it down for safe use in homes and businesses, transformers help maintain a stable and reliable electrical supply.