What is an exposition?

The word exposition comes from the word 'expose'. The word 'expose' means to reveal; display; lay open to something specified. Hence the word exposition means the state of being exposed; a large-scale public exhibition or show, as of art or manufactured products. The word exposition also means the act of expounding, setting forth, or explaining; writing or speech primarily intended to convey information or to explain; a detailed statement or explanation; explanatory treatise. Therefore when asked what is an expostion, one cannot answer directly as there are some definitions of an expostion.