Salvation names deliverance from a fundamental predicament into a final good, and the traditions differ less over the mechanism than over the diagnosis. What salvation is depends on what is thought to be wrong: sin and estrangement from God in the Abrahamic religions; ignorance and bondage to rebirth in the Indian ones; disorder and departure from the Way in the Chinese ones. The English word carries specifically Christian freight, and comparative use of it needs care, moksha, nirvana and salvation are not obviously one thing under three names, and a good deal of nineteenth-century comparative religion went wrong by assuming that they were.
In Judaism the dominant language is redemption, geulah, and it is corporate and historical before it is individual and otherworldly: deliverance from Egypt, from exile, and finally in the messianic age. The world to come and the resurrection of the dead are affirmed, but Judaism does not hold that salvation requires membership in Israel; the righteous of the nations have a share in the world to come, and there is accordingly no missionary imperative.
In Islam, najat or falah is deliverance from the Fire and admission to the Garden, turning on tawhid, submission, right action and above all God's mercy, with intercession affirmed by most Sunni and Shia theology. Because there is no inherited guilt, there is nothing requiring redemption in the Christian sense; what is needed is guidance and forgiveness.
In Hinduism the goal is moksha, release from the round of rebirth, and the Bhagavad Gita names the classical paths, knowledge, action and devotion, as genuine alternatives, with the theistic traditions treating divine grace as decisive. In Buddhism it is nirvana, the extinguishing of craving and the ending of dukkha, and the tradition is deliberate in refusing to describe it as the survival of a self. In Jainism it is the liberation of the jiva from the karmic matter that weighs it down, achieved by one's own effort without divine assistance, which makes Jainism the clearest case of a tradition in which salvation is not given by anyone.