APERTURE refers to the opening of a lens’s diaphragm, which allows light to pass through the camera. It is calibrated in f/stops and is generally written as numbers like 1.4, 2, 2.8 etc. The higher the f/stop, the less light is allowed to pass through the camera.

DEPTH OF FIELD refers to the distance between the nearest and the farthest objects that are in acceptably sharp focus in an image. The depth of field can be calculated based on focal length, distance to subject, the acceptable circle of confusion size, and aperture. The more depth of field, the more focused the camera is to the foreground and the more blurred the background is.