Microwaves are used for many purposes,
among others for heating food. The process of heating food
includes bombarding it with electromagnetic radiation. The
first microwave ovens were introduced in 1947, and they
were very large and used mainly for industrial-military pur-
poses. However, they were quickly integrated into restaurant
kitchens, where they contributed to increased flexibility and
efficiency. Microwaving has also had an important impact on the development of a variety of fast-food products. Some
self-service food outlets have installed microwave ovens for
customers to heat their own food and drinks, and they have
also become a standard amenity in some hotel rooms.