The rule of thirds is a compositional guideline for arranging visual elements in an image so that points of interest are aligned with the intersecting lines of an imaginary three-by-three grid overlaying the image. By placing subjects near these lines rather than at the center of the frame, it is thought to create a more aesthetically pleasing composition that engages the viewer's attention. The document provides examples of how the rule of thirds was applied in several photographs by positioning subjects off-center to direct focus towards specific elements in the image.