Postmodernism is a broad cultural, artistic, and intellectual movement that emerged in the mid-20th century as a reaction against the principles of modernism. It is characterized by skepticism toward grand narratives and ideologies, emphasizing instead the subjective nature of reality and the fragmentation of meaning. Postmodernism often embraces irony, playfulness, and a mix of styles, challenging traditional boundaries in art, literature, and architecture. In literature, postmodernism is marked by techniques such as metafiction and unreliable narrators, as seen in works by authors like Thomas Pynchon and Don DeLillo. In art, it includes movements like Pop Art and Conceptual Art, which blur the lines between high and low culture, questioning the value and purpose of art itself.