Universal gates include NAND and NOR gates. Because they can execute all logic functions of OR, AND, and NOT gates, they are referred to as universal gates.
A universal gate is a type of logic gate that can implement any Boolean function without the usage of any additional logic gates. The universal gates are the NOR and NAND gates. This means that using only NOR or NAND gates, we can build any logical Boolean expression.
The inverse of the AND operation is the NAND gate. NOT AND is represented by the abbreviation NAND.
The NOR gate is the polar opposite of the OR gate. The term NOR stands for NOT OR.