These are minor spirits from the Water Worshiping religions.
Apsara are children of Mell. Innately good, they are said to live among human kind. They grant aid and good luck to those who do good deeds.
Demons are children of Skret. Innately evil, they are said to live in uninhabitable areas. Demons dislike Humans and try to drive them from their territory.
The early Antifordians considered the Vibranni to be demons, living the the harsh desert and not wanting the humans to push them out of their land, and this is still used as a racial slur to describe them.