This is the NOR gate with its truth table. It has 2 inputs (A, B) and 1 output (Out).

The 2 inputs (A, B) can be 0 or 1, and the users can change (0 to 1 or 1 to 0) the value, with a click on each small box of each input.

The output (Out) has connected a red led to signal if the output is 1 or 0 (1 is red led, 0 is led without color).