What does it mean This is the main body of a piece of writing or any of the various forms in which writing exists such as a book a poem an article or a short story?

This statement is emphasizing that the main body of a written work refers to the central, substantial portion that conveys the core content and ideas. It could exist in various forms such as books, poems, articles, or short stories, serving as the primary section where the narrative, argument, or information is developed and presented.