What does a truth table indicate?

A truth table is a comprehensive representation that outlines all possible combinations of inputs and the corresponding outputs for a digital circuit or logical expression. It systematically presents each input state, allowing one to observe how the output changes in reaction to different input configurations. This is essential in digital logic design, as it helps engineers visualize the behavior of logic gates and determine the correct outputs based on specific inputs.

The other options do not capture the full scope of what a truth table represents. For instance, while a truth table implies multiple outputs, it does not directly communicate the total number of outputs (the first option). It also does not calculate an average output level (the third option), nor does it focus solely on a singular output scenario (the fourth option), as it includes all combinations rather than just one. Thus, recognizing that the truth table encompasses all possible input and output combinations is crucial for understanding its intent and application in digital electronics.