Why angels have ring on the head?

The halo, often depicted as a ring above an angel's head, symbolizes their divine nature and holiness. It represents enlightenment, purity, and the presence of God, distinguishing angels as celestial beings. This imagery has been prevalent in art and religious iconography to convey the idea of divine protection and grace. Ultimately, the halo serves as a visual cue of the angel's role as a messenger of God.