A logical or Boolean operation on N-state variables is one that yields a single N-state variable; e.g., a comparison on the 3-state variables A and B, each represented by –, 0, or +, which yields: - when A is less than B, 0 when A equals B, and + when A is greater than B. Specifically, operations such as AND, OR, and NOT on two state variables which occur in the algebra of logic; i.e. Boolean algebra.

Logical operations are also the operations of logical shifting, masking, and other non-arithmetical operations of a computer.