what is a metaphor and simile

A metaphor is comparing something thats not alive to something that is alive.

A simile is saying like or as. 

Smile example: The lion roared as loud as a plane starting up.

                          No one is as fast as a cheetah. 

Metaphor example: The tree waved at us as we walked passed it.

                                The snow was a white blanket on the ground.