20th century literature encompasses an array of diverse aesthetics, styles and approaches. Such a body of work cannot be reduced to a limited or universal set of characteristics. However, certain movements played a significant role in the interpretation and craft of writing, either through changes in technique or reactions to these changes.
Originating in post-WWI Paris, surrealism involved a group of artists who explored the unconscious through unexpected juxtapositions and dissonances. The movement was in part a disillusioned reaction to the rationalism that dominated many forms of 19th century culture and ended in the bloodbath of The Great War. Though the number of official surrealist writers is not extensive, their influence cannot be understated. Everything from Williams S. Burroughs' "cut-up" techniques to the magic realism of Jorge Luis Borges can be traced back to this movement.
Modernist literature flourished in the first half of the 20th century. Its defining principle is subjectivity -- a universal omniscient narrator no longer existed to explain events. All writing comes from individual perspectives and requires interpretation by the reader. Furthermore, modernist literature developed an interest in language and its processes as evidenced in works like James Joyce's "Finnegan's Wake" or Virginia Woolf's "The Waves." As with surrealism, modernist aesthetics were generally pessimistic because of the carnage of WWI.
Postmodernism dominated the second half of 20th century literature. The style should be regarded more as a continuation of modernism than a dramatic break. Like modernism, it embraces relativism, genre and mixes high and low forms of art. Perhaps the greatest difference lies in attitude. Where modernism mourns the meaningless of life, postmodernism celebrates it. While T.S. Eliot broods upon the absurdity of the world in "The Waste Land," David Foster Wallace amuses the reader with many of the same elements in "Infinite Jest."
One of the most significant trends in 20th century literature began toward its conclusion with the advent of the Internet. In the past, books were read in a linear fashion. They all had a beginning, middle and end. However, HTML-enabled hypertext allows readers to pass through a literary work as through a labyrinth of different passageways. New technologies such as the iPad will only encourage and enrich this trend as literature enters the 21st century.