The anti-universe is a theoretical concept in cosmology suggesting the existence of a universe composed entirely of antimatter. It arises from certain interpretations of the Big Bang and the symmetry between matter and antimatter in particle physics. In this framework, the anti-universe would mirror our own universe, with opposite charges and properties, potentially existing alongside it in a way that is not currently observable. This idea raises intriguing questions about the nature of the cosmos and the fundamental laws of physics.