Boolean logic does not just work with numbers. Boolean expressions can also compare text, for example to check if a password is correct.

NOT reverses the input. For a diagram of these actions, see Boolean gates. THIS DEFINITION IS FOR PERSONAL USE ONLY. All other reproduction requires permission.

Here, the output Q is 1 (TRUE) only if inputs C and D are 1 (TRUE). D is only 1 (TRUE) if inputs A and B are 1 (TRUE).

The Boolean logic gates AND, OR and NOT comprise transistors, which are on/off switches wired together. Gates have one or two inputs but only one output, and they are wired in patterns that make ...