Depth of Field refers to the range of distance within a photo that appears sharp and in focus. It is influenced by factors such as the aperture, focal length, and the distance between the camera and the subject. A shallow depth of field results in a blurred background, emphasizing the subject, while a deep depth of field keeps more of the scene in focus. Photographers often manipulate depth of field to create artistic effects or to guide the viewer's attention. For instance, using a wide aperture can isolate a subject, while a narrow aperture is useful for landscape photography, where clarity throughout the image is desired.