We all learned the difference...
We all learned the difference between a metaphor and a simile when we were in grade school. Both give new insights into the nature of a person or a thing by comparing it to something else. A simile does the comparing in a straightforward fashion, telling us that the two things are being compared: The man was built like a bear and smelled nearly as bad as one. A metaphor doesn't tell us that the comparison is being made: The dealer slithered through his presentation and hissed the words to the young man, "At the wheel of this powerful, sleek machine, you will become as a god."