A metaphor is a writing or literary technique that essentially compares two seemingly unrelated objects and finds a way to make the similar by looking for things in common.
In Persepolis, Marjane uses lots of metaphors to better explain her points and ideas. Some of the metaphors used in Persepolis are in The Bicycle, The Key, The Water Cell, The Wine, and many others.

In the chapter "The Bicycle", Marjane compares the Iranian Revolution to a bicycle. "The revolution is like a bicycle. If the weels don't turn, it falls."
In "The Key", the teachers in the public schools give the boys from poor families plastic keys painted gold that they say represent the way into heaven. They say that if the boy's go off to war and "are lucky enough to get killed", that key will get them into heaven.
In "The Wine", the tie that Marjane's father wears is used as a metaphor for westernization. Then man that stops their car and asks for Ebi's license, he says to him, "I can see by your tie! Westernized piece of trash."

There are differnt types of metaphors. Some include:
-a dead metaphor: the sense of a transferred image is not present. ex: grasp a concept.
-a synecdochic metaphor- when a small part of something is used to represent the whole thing. ex: "A pair of ragged claws"-used to describe a crab.