Propositional Calculus, also known as Propositional Logic, is a branch of logic that deals with propositions, which are statements that can be either true or false. It uses logical connectives such as AND, OR, NOT, and IMPLIES to form complex expressions from simple propositions. The primary goal is to determine the truth values of these expressions based on the truth values of their components. In Propositional Calculus, rules and techniques are applied to evaluate logical statements and derive conclusions. This system is foundational in fields like mathematics, computer science, and philosophy, where it helps in reasoning, problem-solving, and constructing valid arguments.