An electrical transformer is a device that transfers electrical energy between two or more circuits through electromagnetic induction. It typically consists of two coils of wire, known as the primary and secondary windings, wrapped around a core. When alternating current flows through the primary winding, it creates a magnetic field that induces a voltage in the secondary winding, allowing for the adjustment of voltage levels. Transformers are essential in power distribution systems, enabling the efficient transmission of electricity over long distances. They can either step up (increase) or step down (decrease) voltage levels, making them crucial for delivering electricity safely to homes and businesses while minimizing energy loss during transmission.