The cosmological argument is a philosophical reasoning that seeks to explain the existence of the universe. It posits that everything that exists has a cause, and since the universe exists, it must have a cause outside itself. This cause is often identified as a necessary being, which many people associate with God. There are several forms of the cosmological argument, including the Kalam cosmological argument and the Aquinas' Five Ways. Each version emphasizes the need for a first cause or an uncaused cause to avoid an infinite regress of causes. This argument is a key topic in discussions about the existence of God and the nature of reality.