Ascension is a process that allows material beings to be able to separate from their physical bodies and become ethereal, allowing them to live eternally as pure energy in a superior plane with greater amount of knowledge and power. It can be a mental, spiritual or evolutionary process, a direct result of obtaining a certain level of wisdom and knowledge.
It has been stated by the Celestial called Adam that the point of the cycle of life, death and rebirth is to enable material beings to achieve Enlightenment so that they can ascend to Heaven.