Actus Reus refers to the physical act or conduct that constitutes a criminal offense. It is one of the essential elements of a crime, alongside Mens Rea, which pertains to the mental state of the offender. Actus Reus can include actions, omissions, or even a state of being that leads to a crime. For example, physically assaulting someone or failing to provide necessary care to a dependent can both be considered Actus Reus. In legal terms, Actus Reus must be proven for a conviction to occur. This means that the prosecution must demonstrate that the defendant engaged in the prohibited behavior. Different crimes have different requirements for what constitutes Actus Reus, but it is always a critical component in establishing criminal liability.