Cross-cutting is an editing technique most often used in films to establish action occurring at the same time in two different locations. In a cross-cut, the camera will cut away from one action to another action, which can suggest the simultaneity of these two actions but this is not always the case.
Suspense may be added by cross-cutting. It is built through the expectations that it creates and in the hopes that it will be explained with time. Cross-cutting also forms parallels; it illustrates a narrative action that happens in several places at approximately the same time. For instance, in D.W. Griffith's A Corner in Wheat (1909), the film cross-cuts between the activities of rich businessmen and poor people waiting in line for bread. This creates a sharp dichotomy between the two actions, and encourages the viewer to compare the two shots. Often, this contrast is used for strong emotional effect, and frequently at the climax of a film. The rhythm of, or length of time between, cross-cuts can also set the rhythm of a scene. Increasing the rapidity between two different actions may add tension to a scene, much in the same manner of using short, declarative sentences in a work of literature.
Cross-cutting was established as a filmmaking technique relatively early in film history (few examples would be Edwin Porter's 1903 short The Great Train Robbery and the Louis J. Gasnier's 1908 short The Runaway Horse) and Griffith was its most famous practitioner. The technique is showcased in his Biograph work, such as A Corner in Wheat and 1911's The Lonedale Operator. His 1915 film, The Birth of a Nation, contains textbook examples of cross-cutting and firmly established it as a staple of film editing. Mrinal Sen has used cross-cutting effectively in his agit-prop film Interview which became quite popular after this. Christopher Nolan uses cross cutting extensively in his films like The Dark Knight, Inception and The Dark Knight Rises where two or three scenes take place simultaneously to build towards a grand climax. Cloud Atlas is known for it's numerous cross-cuts between the film's six different stories, some lasting only a few seconds and spanning across 300+ years in different locations around the world yet held together by similar action between narratives in each cut.
Cross-cutting is sometimes used during phone-conversation scenes so that viewers get to see both characters' nonverbal reactions to what is said.