What is the primary function of a NOR gate?

The primary function of a NOR gate is to output the opposite signal of a corresponding OR gate. This means that a NOR gate will output a low signal (0) when any of its inputs are high (1), and it will output a high signal (1) only when all of its inputs are low (0). This behavior is instrumental in digital circuit design where inversion of logic states is necessary.

In Boolean algebra, the operation of the NOR gate is denoted as the negation of the OR operation. For example, if an OR gate outputs a high signal for any active input, the NOR gate will specifically provide the opposite output, effectively implementing a logical negation of the OR function. This capability makes NOR gates universal gates, meaning they can be used in various combinations to create any digital logic circuit, including AND, OR, and NOT functions. This intrinsic characteristic of a NOR gate is fundamental to understanding its utility in digital electronics and circuit design.