Angels

Archangel Michael battling the Devil:http://www.luckymojo.com/archangelmichael.htmlAngel
Angels are usually viewed as messengers of a supreme divine being, sent to do the tasks of that being. Traditions vary as to whether angels have free will. While the appearance of angels also varies, many views of angels give them a human shape. Angels were initially depicted without wings, but it is common today to see them winged. Despite a common popular belief— or at least metaphor— that angels are former human beings, most major religious organizations deny such a view, and this position is held only by Latter Day Saints and the Bahá'í Faith.

Categories
Initially, there were no distinctions among the angels. By the late fourth century, the leaders in the Christian Church agreed that there were different categories of angels, with appropriate missions and activities assigned to them. For example, Archangel Michael, pictured as a warrior with armor and a sword, is destined to defeat Satan on the Day of Judgment.

Fairy
A fairy is a type of mythological being or legendary creature, a form of spirit, often described as metaphysical, supernatural or preternatural. Fairies are generally described as human in appearance and having magical powers. They could be the spirits of those who died, a species distinct from both humans and angels, or, perhaps, angels that no longer are in Heaven.
Excerpted and adapted from: Angel, Christian teaching about the Devil, Fairy