A microwave oven, or a microwave, is a kitchen appliance that cooks or heats food by dielectric heating. This is accomplished by using microwave radiation to heat water and other polarized molecules within the food. This excitation is fairly uniform, leading to food being more evenly heated throughout (except in thick objects) than generally occurs in other cooking techniques.
Basic microwave ovens heat food quickly and efficiently, but do not brown or bake food in the way conventional ovens do. This makes them unsuitable for cooking certain foods, or to achieve certain culinary effects. Additional kinds of heat sources can be added to microwave packaging, or into combination microwave ovens, to add these additional effects.