theater (warfare)

In warfare, a theater or theatre is normally used to define a specific geographic area within which armed conflict occurs. A war would have to occur over a large portion of the globe in order to be considered large enough to have separate theaters, and the term is not used in the singular. Typically, each theater would be distinct and separate from other theaters. Very often, the delineation occurs along continental boundaries or in separate oceans. Typically, in order to be considered multiple theaters in a single conflict, at least one of the nations involved must be participating in multiple theaters; without this, each area is considered a separate war.
See more at Wikipedia.org...