“Exposition: At the beginning of his play the dramatist is often committed to giving a certain amount of essential information about the plot and the events which are to come. He may also have to give information about what has “already happened”. All this comes under the heading of exposition. A skillful dramatist is able to introduce this material without holding up the action of the play and without recourse to the obvious devices of narrative. See also PROSTATIC CHARACTER.”
Excerpted from: Cuddon, J.A. The Penguin Dictionary of Literary Terms and Literary Theory. New York: Penguin, 1992.