A simile is a comparison of two seemingly dissimilar objects. Its purpose is to make a unique connection between things which appear essentially unlike, usually through using the words "like" or "as." Simile is an important component of effective writing, as it provides the writer with a creative means of description.
The following paragraph, written by a student writer, makes fairly effective use of sensory detail. However, visual imagery could be greatly improved through the addition of simile.