A Devata is a semi-divine being, such as guardian spirit or guardian angel, they generally have a female form in Angkor.
Devatas guarded the sanctuaries devoted to goddesses in 10th century temples, then became omnipresent on the walls of temples built in the 12th century.
Apsaras fall into two main groups, the first is what many scholars call devatas, the elegant semi-devine ladies who adorn and guard the temple walls.
The second group are celestial nymphs, dancers who entertain the gods and the inhabitants of Indra’s Heaven, and are the sensual rewards of kings and heroes who die bravely. In Hindu mythology they always performed with the celestial musicians, Gandharvas, but in Khmer mythology they were elevated alone to special importance in temple decoration.
For more information on apsaras, please see the relevant articles in My Journal.