What is an exposition?

"Definitions of exposition on the Web: a systematic interpretation or explanation (usually written) of a specific topic" (http://www.google.com.sg/search?hl=en&rlz=1C1GGLS_en-USSG292SG304&defl=en&q=define:exposition&ei=qrHQSZ3NNpGNkAW4o9zMCQ&sa=X&oi=glossary_definition&ct=title).

I think exposition is where everything is introduced. The characters, the setting, the time, the place, the problem, the basic essence of any piece of decent text. It is information that is offered to readers to help them understand the plot, characters, or setting in a story. Exposition is "telling, not showing, and passive rather than active" (Bethamos). It is also a tool as it can be used effectively to strengthen the flow of a story. Within the context of fiction, exposition is the fiction-writing mode for conveying information. Exposition in fiction may be delivered through various means, such as through a character of the fiction work, personal journals, and so on. In a nutshell, the purpose of exposition is to inform the readers about the plot, character, setting, and theme of the essay/story.