The racial name for the "humanoid" natives of the Astral Plane. They have two major divisions--angels and devils, based on their primary source of energy. All of the elven races are (distantly) related; the lightborn were those lucians who gave up their immortality to settle in the mortal plane after the Dawn War.
Angels are those who have dedicated themselves to the Great Mechanism, serving as a sort of immune system for the universe. For this they gain endless rebirth and eternal youth with a steady stream of anima from the Great Mechanism itself; they pay with their (eternal) lives. Angels live for nothing but the exercise of their duty; even when relaxing they do so that they may be ready to return to the battlefields.
Devils are those who have chosen (or been forced) to join one of the Diabolical Families. They chose not to devote themselves such; instead they receive payments for services rendered to the Congregation or other ascendants or for services to mortals as part of contracts.
The vast majority of the population are neither angels nor devils; they are simply lucians. Vaguely elf-like in appearance (to mortal eyes, anyway), they tend to the angels and devils and get paid their necessary energy for that service.