Although the most prevalent (and often most fitting) translation is "god," the term deva actually means "shining one." This is an appellation for any superhuman figure, yet it may also be used metaphorically to refer to any high-ranking person, such as a king or a brahmin (priest).
In Hinduism, the concept of "gods" must be understood in the context of reincarnation (samsara), which implies that a person may reincarnate in many distinct realms of reality.
Some are punishment worlds, where individuals atone for the consequences of their poor karma, while others (the heavens) are pleasure realms, where people enjoy the fruits of their good karma.
The devas are the occupants of these heavens, and hence "gods," since gods must dwell in heaven by definition.
All of these gods, even Indra, the king of heaven, are still subject to the vicissitudes of rebirth.
Birth in paradise is predicated on one's good karma, which is eventually reduced by enjoying the benefits of heaven's existence, just as a savings account is depleted by continual withdrawals.
Even gods are liable to reincarnation in other worlds when their good karma is depleted.
Even if these gods are superhuman, the rule of rebirth still applies to them.
Thus, there is a distinction between these gods (the devas) and the so-called Great gods like Vishnu, Shiva, and the Goddess.
These later deities are seen by their followers (bhakta) as completely apart from the realms of space, time, and the causes and consequences of karma, and so more closely resemble the Judeo-Christian concept of "God," as the ultimate authority in the cosmos.
You may also want to read more about Hinduism here.
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