Angels are persons just like human beings, but they have no body. Angels are with God in heaven, and have chosen to stay with him and to serve him. The Bible tells us that angels often act as messengers, for example when the angel Gabriel announced the birth of Jesus (Lk. 1:26), and later his resurrection (Mt. 28:2-6).
Angels watch over people: you too have a guardian angel, who was commissioned by God to accompany you and look after you (Mt. 18:10; Ps. 90:11). The #DeoQuest app contains a prayer to your guardian angel and other angels.