In visual arts including cinematography, framing is a technique used to focus the viewer's attention upon the subject. Framing can make an image more aesthetically pleasing and keep the viewer's focus on the framed object(s).
It can also be used as a repoussoir, to direct attention back into the scene. It can add depth to an image, and can add interest to the picture when the frame is thematically related to the object being framed.