There is a never-ending cycle of birth and death. What is birth and what is death? They are desire. This never-ending cycle is fueled by desire, the desire to enjoy sense objects in a body. When desire ceases, this cycle also ceases. This apparently endless cycle of birth and death ends with the cessation of desire. It is not only birth and death that end. When desire ceases, the universe itself ceases. It is as if it never existed. That's how it is.