High frequency radio waves are electromagnetic waves with frequencies ranging from 3 to 30 megahertz (MHz). They are commonly used for long-distance communication, as they can reflect off the ionosphere, allowing signals to travel beyond the horizon. This property makes them useful for various applications, including amateur radio and maritime communication. These waves can carry voice, data, and other types of information. Devices like transmitters and receivers are used to send and receive these signals. High frequency radio waves are also important in broadcasting, enabling radio stations to reach a wide audience over large areas.