Postmodernism shook up literature by challenging traditional ideas about truth, reality, and meaning. It embraced fragmentation, irony, and skepticism, blurring lines between high and low culture while questioning originality and authenticity in art. Key thinkers like Lyotard, Derrida, and Foucault shaped postmodern thought. Their ideas influenced writing techniques such as metafiction, intertextuality, and fragmentation, leading to groundbreaking works that continue to impact contemporary culture and spark ongoing debates.