In Christian theology, soteriology is the study of spiritual salvation or a series of beliefs and teachings about salvation. It often involves concepts such as faith, repentance, conversion, justification and glorification.
More recently, the term has been applied to all religions and beliefs that involve some idea of “salvation.”¹
Wikipedia tells us that the roots of the word are from Greece:
So to apply it to, say, Buddhism arguably is a bit of a misfit because Buddhism, at the base level, has no concept of God. It also has no concept of a “Self” to be saved.
On the other hand, one could argue, I think fairly enough, that language evolves and we don’t have to stick to the original meanings or roots of words. However, I think it is useful and instructive to understand where words come from, and how their meanings may, perhaps, be adapted to fit political agendas—and not necessarily for accuracy.