What is the difference between a simile and a metaphor?

Simile and metaphor are two closely related rhetorical devices. Both involve making a figurative (nonliteral) comparison between two unlike things or people. But they differ in how they are constructed.

• Simile makes the comparison in the same way you would make a literal comparison: using “as,” “like,” or “than.” For example, “His teeth gleamed like ivory.”
• Metaphor instead makes the comparison using a form of the verb “be” to directly state that one thing “is” the other. For example, “His teeth were ivory.”

Neither comparison is meant to be taken literally, but a metaphor tends to have a more vivid impact since it is more obviously nonliteral.