It is a short story by Garbriel Garcia Marquez. He was a Latin American author and many of his stories are Magical Realism. This story has all the characteristics of Magical Realism, such as having one fantastic element while being reality based, having a deeper meaning, and having no need to justify or explain events or human actions. The angel is the element in Magical Realism that discovers the mysterious parts in life.
Most people believe in supernatural beings like angels.
Angels are usually thought of as protecting and taking one to the afterlife. The angel was believed to have come to take the baby to heaven. Another magical element was the sicknesses of the people who came to be healed by the angel. The realistic elements include everything else in this story. The people's curiosity to the angel and the lady spider are authentic.