A microwave oven uses electromagnetic waves called "microwaves" for heating foods. Microwaves are a type of radio wave with a frequency range typically between 300 MHz (megahertz) and 300 GHz (gigahertz). These waves are part of the electromagnetic spectrum, which also includes radio waves, infrared radiation, visible light, ultraviolet radiation, X-rays, and gamma rays.
Inside a microwave oven, an electronic component called a magnetron generates microwaves. These microwaves are then directed into the oven's cooking area, where they interact with the water molecules present in the food. The microwaves cause the water molecules to vibrate rapidly, which generates heat. This heat is what cooks or heats the food evenly and quickly, making microwave ovens a convenient and popular kitchen appliance for food preparation.