Most people have no trouble understanding the simple, surface difference between a simile and a metaphor. They both serve to make comparisons, but similes use comparison words such as “like” or “as,” whereas metaphors do not. Two examples of simile from my second novel-in-progress, The Experiment, are:

Maybe he could make more of the next 23 hours … if he weren’t so aware of the minutes peeling away like sheets on a desk calendar.

Her pen moved slowly, like her morning thoughts.

To help express the character’s sense of time passing too quickly, the first example draws a comparison between minutes passing and the sheets on a desk calendar being ripped away and discarded. The second example compares the pace of the writer’s pen to the pace of her thoughts–both slow in the early morning hours.

An example of a metaphor from the same work is:

 …the sky had exchanged its vibrant afternoon blue for a pale lavender nightgown.

In the above example, dusk is compared to (almost equated with) a “pale lavender nightgown” the personified sky dons before nightfall.

When a writer employs a simile, she allows for a degree of separation between the items she compares. They are similar, alike–but not the same. By contrast, a metaphor essentially equates the items it compares. When a writer uses a metaphor, she is implying a much closer comparison than if she uses a simile. As a reader, paying attention to this subtle difference can help you ascertain author’s purpose and better comprehend a character, scene, and so forth. As a writer, be aware of the fact that making comparisons through a simile or a metaphor can produce different effects. A metaphor creates a more direct comparison than does a simile. The choice you make as a writer depends on how close a comparison you intend to draw, or how close a relationship you want to create between the two subjects.

When a writer employs a simile, she allows for a degree of separation between the items she compares. They are similar, alike–but not the same. By contrast, a metaphor essentially equates the items it compares. When a writer uses a metaphor, she is implying a much closer comparison than if she uses a simile.

To see a visual representation of the subtle differences between simile and metaphor, please see this Venn Diagram.