A Power Supply is an electrical device that provides power to an electrical load, converting available electrical energy into the necessary voltage and current for the device's operation. It can transform AC (alternating current) from the main power source into DC (direct current) or adjust voltage levels for various applications, ensuring a stable energy flow.

A Transformer, on the other hand, is an electrical device that transfers electrical energy between circuits through electromagnetic induction. It is primarily used to increase (step-up) or decrease (step-down) the voltage levels of an AC supply to suit the power requirements of different devices or systems.

Both power supplies and transformers are widely used in electronic devices, industrial machinery, and electrical infrastructure to ensure safe and efficient power distribution.