Celestial does not mean the same thing at all. Celestial Magic is involved with summoning celestial spirits. Those spirits are entities of their own and even live in different dimensions and in some cases, are summoned from a universe that they don't live in. Divine and holy magic are related but not entirely the same. While holy does focus on the works of the Angels and such that involves healing, divine magic focuses more on the punishing power of the holy arts. Mostly focusing of banishing evil to hell or burning them with white flame.