There's a big debate about postmodernism. Mostly this debate revolves around nobody really having any clue what postmodernism really is at all. There is a plethora of theories and ideas about postmodernism, but since it wasn't really a true break from the Modern, it doesn't really have a concrete definition.
First, we could look at postmodernism linguistically. Post is a prefix, but it has a few meanings. Against, after, resulting? But how does that relate to modernism? How is it against modernism if it still incorporates ideas from modernism? How is it after modernism, if modernism principles still stand? This is exactly why we can't put a definition on the postmodern.
We discussed two theories in class, Lyotard's theory and Baudrillard's theory. But what it basically boils down to is that no one knows. What happened is that modernism "ended" and thereby postmodernism was born. But the modern didn't really end, it just evolved.
The modernist art, the flat paintings, the post-painterly abstractionists, shapes and colors and non-representation, it all changed into installations and performance. It became about making a statement. The feminists, the Guerrilla Girls, Sherrie Levine and Mapplethorpe. Artists weren't just making art, they were bending the rules. They were changing the way society interpreted them.
Not only were they artists, but they were curators, critics, philosophers. There are no rules anymore. Artists were doing more than art, they were using math and intellect. Creating perspectives and philosophies about their own art. They no longer needed a critic to tell the rest of the world what their art meant because now they could do it themselves. There were no limits, no constraints.
It started in the later 60s and has evolved into the art world that we have today. Take the college that I am attending for example - I don't attend the College of Art. My friends don't go to the College of Architecture. I don't know people who are in the College of Design either. This is because we are all part of the same college, the College of Art and Architecture, which was unheard of before these "hippy" artists decided to take a stand.
So, what is Postmodernism? Postmodernism is now. It's you. It's me. It's us.