What exactly happens after death according to Hinduism

According to Hinduism, What exactly happens after death is a doubtful question among Hindus. Because no one knows the correct explanations for that. Nevertheless each of them has different opinions about the happenings after death. Hindus are believing in so many concepts such as rebirth. The idea of rebirth is evolved in Upanishads and fully described in Puranas. Actually anything that is born will die at one day. In fact anything that is born will die forever at one day. After death one's body will be buried or burnt and soul will immediately enter into another womb. Some of them are believing that soul will leave the body only after the accounts of Karma are finished. At the time of death, there will be an absence of fear, sorrow, afraid and one will experience peace of mind through bliss. This type of death is called "Samadhi Maran". Hindu concept is believing that  after death is renouncing the body or Samadhi, that means self termination of life after fulfilling duties in the world. According to that, among Hindu people men are following four ways after death. The first one is Devayana is the path of Gods. One who leads spiritual and pure life will attain devayana by devoting to Brahman through meditation before death. But if some one has not completed the self knowledge before death will replaced to the highest heaven, Brahmaloka. The second Pitriyana is one who has the wish to do charity, worship etc and they will repair to Chandraloka and after that will get reward for the good deeds and return to earth to complete earthly desires. If one who leads impure life by doing bad deeds will born in sub human species. One who is depraved in thoughts and deeds will again reborn as mosquitoes and fleas. Humans can go only into another humans is the another confusing matter arising among Hindus. Once human is born and to move around the four different life forms such as human, celestial, animal and hell. A scientific evidence is that goddess Vidhata, a nature, will come and writes the future life of a baby on the sixth day after baby's birth. People are believing that Moksha or liberation will get after death within one or two births. Some Hindus believes that after death, Soul may enter Swarg or Narak for a duration before reincarnation. People are believing the incidents after death is divided as two. One who is believing about the live only once after death and about multiple lives. Live only once is after death, will enter into either heaven or hell. But multiple lives are coming back from Pitr-loka to Bhu-loka. Some variations are also described in that is, punished one for different crimes will be in hell or narakaloka will reborn or where you enjoy Swargaloka is time to return to earth again.