What is a truth table?

A truth table is a fundamental tool used in digital logic design that systematically lists all possible combinations of inputs to a logic circuit and their respective outputs. It clearly demonstrates how the output value changes based on varying input values, making it essential for understanding and analyzing the behavior of logical operations.

For instance, if a circuit has two inputs, A and B, a truth table will include all combinations of A and B, such as (0, 0), (0, 1), (1, 0), and (1, 1), and show what the output is for each pair based on the logic defined by the circuit. This representation helps engineers and student practitioners visualize and validate logic functions, proving valuable when designing or troubleshooting circuits.

The other choices represent related concepts but do not define a truth table accurately. Summarizing logic gates provides a different type of information, while simplifying Boolean expressions pertains to optimizing logic without detailing inputs and outputs. A logic circuit diagram additionally provides a graphical representation but does not convey the same systematic listing that a truth table does.