A truth function is a type of logical function that takes in one or more pieces of information and then produces a single answer such as true or false. For example, if we have two pieces of information, A and B, and we want to know whether A is true or false, a truth function can help us. Let's say A is "the sky is blue" and B is "the grass is green", a truth function would produce an answer of true because both of the statements are true.