Modernism = a general term applied retrospectively to the wide range of experimental and avant-garde trends in the literature (and other arts) of the early 20th century, including Symbolism, Futurism, Expressionism, Imagism, Vorticism, Dada, and Surrealism, along with the innovations of unaffiliated writers.
Modernist literature is characterized chiefly by a rejection of 19th-century traditions and oftheir consensus between author and reader: the conventions of realism, for instance, were abandoned by Franz Kafka and other novelists, and by expressionist drama, while several poets rejected traditional metres in favour of free verse.
Modernist writers tended to see themselves as an avant-garde disengaged from bourgeois values, and disturbed their readers by adopting complex and difficult new forms and styles. In fiction, the accepted continuity of chronological development was upset by Joseph Conrad, Marcel Proust, and William Faulkner, while James Joyce and Virginia Woolf attempted new ways of tracing the flow of characters' thoughts in their stream-of-consciousness styles. In poetry, Ezra Pound and T. S. Eliot replaced the logical exposition ofthoughts with collages of fragmentary images and complex allusions. Luigi Pirandello and Bertolt Brecht opened up the theatre tonew forms of abstraction in place of realist and naturalist representation. Modernist writing is predominantly cosmopolitan, andoften expresses a sense of urban cultural dislocation, along with anawareness of new anthropological and psychological theories. Its favoured techniques of juxtaposition and multiple point of view challenge the reader to reestablish a coherence of meaning from fragmentary forms. In English, its major landmarks are Joyce's Ulysses and Eliot's The Waste Land (both 1922).
Modernists felt a growing alienation incompatible with Victorian morality, optimism, and convention. The Modernist impulse is fueled in various literatures by industrialization and urbanization, by the search for an authentic response to a much-changed world. Among English-language writers, the best-known Modernists are T.S. Eliot, James Joyce, Gertrude Stein, and Virginia Woolf.

Differences between Modernism and Postmodernism
Modernism is an encompassing label for a wide variety of cultural movements. Postmodernism is essentially a centralized movement that named itself, based on socio-political theory, although the term is now used in a wider sense to refer to activities from the 20th Century onwards which exhibit awareness of and reinterpret the modern.
Postmodern theory would assert that the attempt to canonise Modernism "after the fact" is doomed to undisambiguable contradictions.
In a narrower sense, what was Modernist was not necessarily also Postmodern. Those elements of Modernism which accentuated the benefits of rationality and socio-technological progress were only Modernist.

Postmodernism = a disputed term that has occupied much recent debate about contemporary culture since the early 1980s. In its simplest and least satisfactory sense it refers generally to the phase of 20th-century Western culture that succeeded the reign of high modernism, thus indicating the products of the age of mass television since the mid-1950s. More often, though, it is applied to a cultural condition prevailing in the advanced capitalist societies since the 1960s, characterized by a superabundance of disconnected images and styles—most noticeably in television, advertising, commercial design, and pop video. In this sense, postmodernity is said to be a culture of fragmentary sensations, eclectic nostalgia, disposable simulacra, and promiscuous superficiality, in which the traditionally valued qualities of depth, coherence, meaning, originality, and authenticity are evacuated or dissolved amid the random swirl of empty signals. As applied to literature and other arts, the term is notoriously ambiguous, implying either that modernism has been superseded or that it has continued into a new phase.
Postmodernism may be seen as a continuation of modernism's alienated mood and disorienting techniques and at the same time as an abandonment of its determined quest for artistic coherence in a fragmented world: in very crude terms, where a modernist artist or writer would try to wrest a meaning from the world through myth, symbol, or formal complexity, the postmodernist greets the absurd or meaningless confusion of contemporary existence with a certain numbed or flippant indifference, favouring self-consciously ‘depthless’ works of fabulation, pastiche, bricolage, or aleatory disconnection. The term cannot usefully serve as an inclusive description of all literature since the 1950s or 1960s, but is applied selectively to those works that display most evidently the moods and formal disconnections described above. It seems to have little relevance to modern poetry, and limited application to drama outside the ‘absurdist’ tradition, but is used widely in reference to fiction, notably to the novels (or anti-novels) and stories of Thomas Pynchon, Kurt Vonnegut, Italo Calvino, Vladimir Nabokov, William S. Burroughs, Angela Carter, Salman Rushdie, Peter Ackroyd, Julian Barnes, Jeanette Winterson, and many of their followers. Some of their works, like Pynchon's Gravity's Rainbow (1973) and Nabokov's Ada (1969), employ devices reminiscent of science fiction, playing with contradictory orders of reality or the irruption of the fabulous into the secular world.

Reaction to modernism
Postmodernism was originally a reaction to modernism. Largely influenced by the Western European "disillusionment" induced by World War II, postmodernism tends to refer to a cultural, intellectual, or artistic state lacking a clear central hierarchy or organizing principle and embodying extreme complexity, contradiction, ambiguity, diversity, interconnectedness or interreferentiality, in a way that is often indistinguishable from a parody of itself. It has given rise to charges of fraudulence.
Postmodernity is a derivative referring to non-art aspects of history that were influenced by the new movement, namely developments in society, economy and culture since the 1960s. When the idea of a reaction or rejection of modernism was borrowed by other fields, it became synonymous in some contexts with postmodernity. The term is closely linked with poststructuralism (cf. Michel Foucault) and with modernism, in terms of a rejection of its bourgeois, elitist culture.

POSTMODERN LITERATURE
Notable influences
Postmodernist writers often point to early novels and story collections as inspiration for their experiments with narrative and structure: Don Quixote, 1001 Arabian Nights, The Decameron, and Candide, among many others. In the English language, Laurence Sterne's 1759 novel The Life and Opinions of Tristram Shandy, A Gentleman, with its heavy emphasis on parody and narrative experimentation, is often cited as an early influence on postmodernism. There were many 19th century examples of attacks on Enlightenment concepts, parody, and playfulness in literature, including Lord Byron's satire, especially Don Juan; Lewis Carrol's playful experiments with signification; the work of Arthur Rimbaud, Oscar Wilde.
Playwrights who worked in the late 19th and early 20th century whose thought and work would serve as an influence on the aesthetic of postmodernism include Swedish dramatist August Strindberg, the Italian author Luigi Pirandello, and the German playwright and theorist Bertolt Brecht. In the 1910s, artists associated with Dadaism celebrated chance, parody, playfulness, and attacked the central role of the artist. Tristan Tzara claimed in "How to Make a Dadaist Poem" that to create a Dadaist poem one had only to put random words in a hat and pull them out one by one. Another way Dadaism influenced postmodern literature was in the development of collage, specifically collages using elements from advertisement or illustrations from popular novels (the collages of Max Ernst, for example). Artists associated with Surrealism, which developed from Dadaism, continued experimentations with chance and parody while celebrating the flow of the subconscious. André Breton, the founder of Surrealism, suggested that automatism and the description of dreams should play a greater role in the creation of literature. Surrealist René Magritte's experiments with signification are used as examples by Jacques Derrida and Michel Foucault. Foucault also uses examples from Jorge Luis Borges, an important direct influence on many postmodernist fiction writers. He is occasionally listed as a postmodernist, although he started writing in the 1920s. The influence of his experiments with metafiction and magical realism was not fully realized in the Anglo-American world until the postmodern period.
Comparisons with modernist literature
Both modern and postmodern literature represent a break from 19th century realism, in which a story was told from an objective or omniscient point of view. In character development, both modern and postmodern literature explore subjectivism, turning from external reality to examine inner states of consciousness, in many cases drawing on modernist examples in the stream of consciousness styles of Virginia Woolf and James Joyce, or explorative poems like The Waste Land by T. S. Eliot. In addition, both modern and postmodern literature explore fragmentariness in narrative- and character-construction. The Waste Land is often cited as a means of distinguishing modern and postmodern literature. The poem is fragmentary and employs pastiche like much postmodern literature, but the speaker in The Waste Land says, "these fragments I have shored against my ruins". Modernist literature sees fragmentation and extreme subjectivity as an existential crisis, or Freudian internal conflict, a problem that must be solved, and the artist is often cited as the one to solve it. Postmodernists, however, often demonstrate that this chaos is insurmountable; the artist is impotent, and the only recourse against "ruin" is to play within the chaos. Playfulness is present in many modernist works (Joyce's Finnegans Wake or Virginia Woolf's Orlando, for example) and they may seem very similar to postmodern works, but with postmodernism playfulness becomes central and the actual achievement of order and meaning becomes unlikely.
The prefix "post," however, does not necessarily imply a new era. Rather, it could also indicate a reaction against modernism in the wake of the Second World War.