What is Afterlife
Some faiths believe that there is only one life to live and beyond that the person either goes to hell or heaven whereas there are some belief systems which believe in reincarnation whereby a soul gets a new lifeform and is reborn which could be a human or any animal, bird etc.
Afterlife in Christianity & Islam
Christianity and Islam belive in an afterlife which will be in either heaven or hell. This will decided on the "Judgement Day" and then all the dead will be resurrected and sent to heaven and hell.
Afterlife in Hinduism, Sikhism, Buddhism, Jainism
Hinduism, Sikhism, Buddhism, Jainism belive in reincarnation. The belief is that a soul continues to wander in various lifeforms until it attains moksha (salvation). Sikhism, Buddhism and Jainism can be considered offshoots of Hinduism and therefore the beliefs are almost identical. We will discuss Hinduism in the end as that is the most elaborate religion in terms of any spiritual experiences.