Microwaves are a type of electromagnetic radiation, and not a compound. They are part of the electromagnetic spectrum, which includes radio waves, infrared radiation, visible light, ultraviolet radiation, and X-rays. Microwaves have a wavelength range from about 1 millimeter to 1 meter and a frequency range from 300 MHz to 300 GHz. They are used in various applications, including microwave ovens, communication systems, and radar systems.