A Story is a view of your album. Any photos, videos, gifs, and descriptions in your album will show in story view.
When you add, remove, or re-arrange content in an album, the story will automatically update for you.
All of the photos, videos, and animated gifs in an album will show in the story.
Your photo descriptions will show automatically as accompanying text. Descriptions can be added below the image, when viewing the image in the full view within your album.