A type of bipolar transistor in which a base of N-type material is sandwiched between an emitter and a collector of P-type material. The base, emitter, and collector are the three terminals of the transistor through which current flows. In a PNP transistor, holes (electron “vacancies”) are the majority of the charge carriers, and they flow from the emitter to the collector. See the illustration. See also N-type semiconductor, P-type semiconductor. Compare NPN transistor.