The term "actus" originates from Latin, meaning "act" or "action." In various contexts, it refers to a deed or an event that is performed. In philosophy, particularly in the works of Aristotle, "actus" is often contrasted with "potentia," which signifies potentiality or the capacity to act. In legal terminology, "actus" is used in phrases like "actus reus," which refers to the physical act of committing a crime. This concept is essential in criminal law, as it helps establish the actions that constitute an offense, distinguishing between mere thoughts and actual conduct.