A simile is a figure of speech involving the comparison of one thing with another thing of a different kind; It is used to make a description more emphatic or vivid.
Example:
As brave <u>as</u> a lion.
As you can see, this uses as, which states that the subject is acting as brave as a lion.
Crazy <u>like</u> a fox.
As you can see, this uses like, which states that the subject is acting as crazy as a fox.
