High frequency refers to a range of electromagnetic waves or sound waves that oscillate at a high rate. In the context of radio waves, high frequency (HF) typically ranges from 3 to 30 megahertz (MHz). These waves are used for various communication purposes, including amateur radio and shortwave broadcasting, allowing signals to travel long distances by reflecting off the ionosphere. In audio terms, high frequency describes sounds that are at the upper end of the audible spectrum, generally above 2,000 hertz (Hz). High-frequency sounds include those made by instruments like flutes or cymbals, and they contribute to the brightness and clarity of music. Understanding high frequency is essential in fields like acoustics and telecommunications.