The term "beat signal" refers to a signal that results from the addition or subtraction of two signals of slightly different frequencies. There are different synonyms that can be used to describe this type of signal, depending on the context in which it is used. In electronics, the term "heterodyne signal" is often used to describe the same phenomenon. This term is frequently used in radio communication applications, where it refers to a signal that is created when a received signal is mixed with a local oscillator signal of a slightly different frequency. In physics, beat signals may also be referred to as "interference signals" or "modulated signals".