An interference pattern is an alternating light and dark bands, known as fringes, that are produced by interference. In general, the pattern of peaks and troughs that results when two or more waves that traveled slightly different paths from the same source are brought together. The term is also used in radio astronomy, to describe the pattern that results when the signals picked up by two or more elements of an interferometer are combined; interference is the basic principle used in interferometry to increase resolving power.