What is frequency

In physics, the term frequency refers to the number of waves that pass a fixed point in unit time . It also describes the number of cycles or vibrations undergone during one unit of time by a body in periodic motion.

A radio communications signal must occupy a range of frequencies carrying most of its energy, called its bandwidth. A frequency band may represent one communication channel or be subdivided into many . Allocation of radio frequency ranges to different uses is a major function of radio spectrum allocation.

Communications. Radio frequencies are used in communication devices such as transmitters, receivers, computers, televisions, and mobile phones , to name a few. Radio frequencies are also applied in carrier current systems including telephony and control circuits.