Dadaism and surrealism are two distinct cultural movements though they both help to define the parameters of Modernism.

Dadaism came first, emerging originally in Zurich, as a direct response to the horror and pointlessness of World War I. Artists, writers, and other intellectuals who subscribed to Dadaism were unique in their individual interpretations of Dadaism, but they all rejected ideals that had to do with the notion of progress. After all, World War I was proof of the absurd uselessness of progress; in the context of the war, progress meant manipulative propaganda and the mass killing of young innocents. The absurdist style of Dadaist art functioned as a protest against these violations of society.

Surrealism came later, and though surrealism was also inspired by a sense of severe disappointment, it was a more structured movement that focused on the unconscious and uncontrollable experiences like dreams. Surrealists played with rational images and ideas, disorienting the public in a deliberate way.

In the early 20th century, art, especially literature and drama, began to move away from Realism, the overwhelming impulse of the 19th century.  It moved away in several directions:  Surrealism (literally, above realism) sought to examine and depict a reality above the three-dimensional realism with ties to Time; dreams are often associated with this departure; Dada (not Dadaism) was a term invented by those who wanted to move outside the boundaries of logic, sense, cause-and-effect thinking, away from thinking itself (there are several explanations for the name; the most often accepted is that they picked the name at random from a dictionary, so that it “meant” nothing at all).  Other movements (expressionism, futurism, absurdism) had other agendas.  The difference in the two movements, then, in literature, are these:  Surrealist works set up their own logic, free from physical laws, etc., but with an internal “logic” of their own.  Dada, on the other hand, not only avoided common logic, but also did not try for any “internal” system or order of its own.  Thus we have Ubu Roi  by Alfred Jarry, or August Strindberg’s A Dream Play as surrealist dramas.  Artaud's play, Jet of Blood is also considered a surrealist play.  A better example of Dada for the stage would be Tristan Tzara's Gas Heart.