A bright ring or circle of light typically hovering above or traditionally behind the head that either symbolizes purity or to denote that the character is an angel or saint. This tag applies generally to all kinds of halos which hover over one's head, such as a mechanical halo, not just those that are considered traditional - for such halos only, see traditional halo.
Currently, the most common usage of halos on Danbooru are in Blue Archive due to the abundance of students with unique halos hovering over their heads, which symbolize each individual's personality and their citizenship in the academic city of Kivotos.
Not to be confused with the optical phenomenon caused by ice crystals in the atmosphere surrounding the sun or moon, forming a halo (see External Links), or halo-like artifacts of light caused by bright light sources interacting with the camera lens. The latter is a lens flare.
