Microwaves are a form of electromagnetic radiation, and as such, they are able to penetrate food and cause the water molecules within to vibrate. This vibration creates heat, which cooks the food. Microwaves are an efficient way to cook food because they heat the food evenly and quickly. In addition, microwaves do not cause the loss of nutrients that can occur with other cooking methods, such as boiling. Microwaves are also very versatile and can be used to cook a wide variety of foods. As a result, they have become a staple in many kitchens.