The word "Angel" means litterally "messenger". Angels are merely messengers of God. They have nothing to offer in the way of technilogical advances. Their purpose is merely to be agents of God's will. Other than that they are the residents of heaven, sinless beings living in perfect harmony with God. On the otherhand there are also the fallen angels. Those who chose to follow Satan when there was war in heaven. These are the demons, the evil spirits who battle for our souls. This is the Christian veiw of angels, I don't know that angels exist outside of Christianity and Judaism.