Angels were created by God. Angels are not to be worshipped. Angels are not omnipresent. Some angels help human beings.
Some angels are cherubim.
Some angels are Seraphim. Their purpose is to glorify God. God employs the ministry of angels to deliver his people from affliction and danger, and that the angels do not think it below their dignity to minister even to children and to the least among Christ's disciples. Michael takes souls to the other world, In Revelations, it is Michael who leads an army of God's angels against Satan. He is often depicted with a sword.