NOT gate, XNOR gate in DLD Digital Logic Design

What is NOT Gate or inverter?

NOT Gate works as Inverter. NOT Gate performs an inversion function. The Not Gate must have single input and output. NOT Gate is represented in the figure below;

inverter logic gate
Figure: NOT Gate
Input Output
0 1
1 0

What isĀ Exclusive-NOR Gate?

XNOR Gate performs a function that is equivalent to the combination of OR, AND and NOT gates.

Exclusive NOR gate
Figure: XNOR Gate
Inputs Output
0 1
0 1 0
1 0 0
1 1 1