When referring to a DVD a chapter is a portion of the overall movie. For example, a DVD movie have several chapters that allow the viewer to skip through a movie one chapter at a time, making the process of skipping through a movie much faster. The picture is an example of the chapter button found in a software program or on a remote.
With some devices and programs, there may only be a fast forward button with no additional chapter button. In this situation, the fast forward button may be used as a chapter skip button if pressed once or a fast forward button if held down.