A logic gate is an elementary building block of a digital circuit. Most of the logic gates have two inputs and one output. At a point, every terminal is in one of the two binary representations 0&1. There are seven logic gates: AND, OR, XOR, NOT, NAND, NOR, and XNOR. A logic gate implements a Boolean function and it basically performs a logical operation on the logic inputs, in order to produce a single logic output.
