“The struggle that grows out of the interplay of two opposing forces. Conflict provides interest, suspense, and tension. At least one of the opposing forces is customarily a person. This person, usually the protagonist, may be involved in conflicts of four different kinds: (1) a struggle against nature…(2) a struggle against another person, usually the antagonist…(3) a struggle against society…or (4) a struggle for mastery by two elements within the person…Seldom do we find a simple, single conflict, but rather a complex one partaking of two or even all of the preceding elements…Conflict implies not only the struggle of a protagonist against someone or something, but also the existence of some motivation for the conflict or some goal to be achieved thereby. Conflict is the raw material out of which plot is constructed” (Source: Harmon & Holman, p 115-116).
Also see: plot.