Complimentary Metal Oxide Semiconductor

Complementary metal–oxide–semiconductor (CMOS) ("see-moss", ), is a major class of integrated circuits. CMOS technology is used in chips such as microprocessors, microcontrollers, static RAM, and other digital logic circuits. CMOS technology is also used for a wide variety of analog circuits such as image sensors, data converters, and highly integrated transceivers for many types of communication.
See more at Wikipedia.org...

a circuit that combines PMOS and NMOS devices in pairs. CMOS circuits only consume power when they are switching state. See also, NMOS and PMOS.

see, Complimentary Metal Oxide Semiconductor.