Logic gates/NOR

NOR = NOT-OR  ~   Therefore this indicates that the result of the inputs placed through the gate will go through the OR operation and the NOT operation. The correct order of processing is: Step 1. Put the inputs through the OR operation. Step 2. From the results of the first step - invert (using the NOT operation). Step 3. Take the result from Step 2 as the output.

Rules of a NOR gate
A NOR gate is a logic gate which follows the rules of the truth table below:

Circuit Symbol
The NOR gate is represented within a circuit diagram using the following circuit symbol:



In the example to the left we can see that A & B are the inputs and the output is the result of A & B processed through the "OR" operation and then the value is inverted. This is represented using a method of notation called "DeMorgans Logic Notation".