A logic gate performs a logical operation on one or more logic inputs and produces a single logic output. The logic is called Boolean logic and is most commonly found indigital circuits. Logic gates are primarily implemented electronically using diodes or transistors, but can also be constructed using electromagnetic relays (relay logic), fluidic logic, pneumatic logic, optics, molecules, or even mechanical elements. The simplest form of electronic logic is diode logic. A Digital Logic Gate is an electronic device that makes logical decisions based on the different combinations of digital signals present on its inputs. A digital logic gate may have more than one input but only has one digital output. Standard commercially available digital logic gates are available in two basic families or forms, TTL which stands for Transistor-Transistor Logic such as the 7400 series, andCMOS which stands for Complementary Metal-Oxide-Silicon which is the 4000 series of chips. This notation of TTL or CMOS refers to the logic technology used to manufacture the integrated circuit, (IC) or a "chip" as it is more commonly called.