exposition
     n 1: a systematic interpretation or explanation (usually written)
          of a specific topic [syn: {expounding}]
     2: a collection of things (goods or works of art etc.) for
        public display [syn: {exhibition}, {expo}]
     3: an account that sets forth the meaning or intent of a
        writing or discourse; "we would have understood the play
        better if there had been some initial exposition of the
        background"
Source: WordNet® 2.0