The main characteristic of a JK flip-flop typically refers to its truth table, which outlines its operational behavior. Some participants suggest that it could also relate to the equations governing the flip-flop's state transitions, although this is less common. The truth table and characteristic equation essentially convey the same information about the flip-flop's function. The choice between using the truth table or the equation depends on the context of the discussion. Clarification on the terminology used in the original question is necessary for accurate understanding.