Eventually we find that angels cannotwork miracles, but they can perform many special effects that appear miraculous, such as protecting Daniel from the lions in Daniel 6. When angels appear to man, they usually appear with wings, but the wings are not the method of locomotion. The primary general duty of angels is as messengers of God. But angels can do God's chores, such as busting Peter out of jail in Acts 5, or destroying Sodom and Gomorrah in Genesis 19. Satan had been an angel, but decided to do his own thing.
Angels can see all aspects of a situation instantly, since they are so very wise.
Angels, and the dimensions they live in, were apparently created before our visible world and universe. The number of angels are countless. Additionally, some people who have died may have been transformed into lower angels. Speaking of miracles, some people believe that the reason more asteroids don't hit and damage planets is because each planet also has a guardian angel. In this school of thought, we owe our very existence to angels guiding our destiny.