Shortwave radios are devices that can receive radio signals transmitted over long distances using shortwave frequencies, typically between 3 and 30 MHz. These radios are popular for international broadcasting, allowing users to listen to stations from around the world, including news, music, and cultural programs. The technology behind shortwave radios relies on the ionosphere, a layer of the Earth's atmosphere that reflects radio waves back to the ground. This enables signals to travel beyond the horizon, making it possible to connect with distant stations. Many enthusiasts enjoy using shortwave radios for emergency communication and hobbyist listening.