What is the post modern frame in art?

Modernism is generally wrapped around the belief that the world is constantly improving itself and moving toward a greater, more perfect whole.

Postmodernism is generally wrapped around the idea that the world changes, that ideas change, and that some ideas work better than others, but that there is no "right" way of doing things. Postmodernism challenges the way society has structured the world and does not like to categorize people or art. It does not believe in progress.