A microwave oven is an electric oven that heats and cooks food by exposing it to electromagnetic radiation in the microwave frequency range. This causes the polar molecules in food to rotate and heat energy to be produced in a process called dielectric heating. You can directly control the cooking time to better control the amount of energy you use. It also doesn't retain heat and doesn't overheat everything in your kitchen. Microwaves use less energy than any conventional oven or stove because they heat water directly on food.