Just as in conventional life on Earth, there are a range of
"afterlife" experiences.
Basically, there are six possible realms, three lower realms and
three higher realms. The lower realms are the hell realm, the
hungry ghost realm and the animal realm. The higher realms are the
human realm, the jealous god realm and the god realm. All of these
realms are subject to karma and rebirth in any of the other
realms.
Nirvana, though, is not a realm, as such, but an unconditioned
spiritual state that is beyond the six realms. One is no longer
subject to karma. One has gone beyond karma. This is an
inexpressible state which must be realized within oneself to be
understood. This is our natural state of awareness once we have
realized our original nature.