Propositional Logic in Artificial Intelligence (AI) is a formal system used to represent and reason about facts and relationships in a structured and unambiguous way. It consists of propositions, which are statements that can be either true or false, and logical connectives such as AND, OR, NOT, IMPLICATION, and BICONDITIONAL. In AI, propositional logic is used for knowledge representation, automated reasoning, and decision-making. It enables inference through rules of deduction, such as Modus Ponens and Resolution, allowing AI systems to derive new knowledge from existing facts. However, while propositional logic is useful for simple reasoning tasks, it lacks expressiveness for handling complex domains involving variables, quantifiers, or uncertainty, which are addressed by more advanced logical systems like First-Order Logic and Probabilistic Logic.