Much of what we do as writers is to fulfill a given purpose: to entertain, inform, persuade, or reveal, among other things. If the point of a given passage or scene is to make a statement, hyperbole is a good way to do it. This technique can be defined as exaggeration used for the sake of emphasis, and can be better understood through the following setting description example.

       Marcy’s dorm room offered a scary look into the aftermath of the apocalypse—beds were buried in lumps of clothing and shoes, granola bar wrappers and crumbs peppered the floor, and a sour smell hung in the air, likely a product of the bacterial experiment disguised as a dirty stack of dishes in the sink.

The author uses a few exaggerations here that can’t possibly be true. Marcy’s room isn’t the site of an apocalyptic event, and the contents of the sink are more likely yesterday’s dishes than a scientific experiment gone wrong. Readers know that the writing isn’t literal, yet the author’s message (Marcy is a slob) comes through loud and clear. Through the use of hyperbole, the heroine has been characterized clearly and humorously, and the purpose of this description has been accomplished.