Auto mode tells your camera to use its best judgement to select shutter speed, aperture, ISO, white balance, focus and flash to take the best shot that it can. Portrait mode selects a large aperture, and it helps keep your background out of focus. Landscape mode is almost the opposite of portrait mode this sets your camera up with a small aperture. Sports mode helps shoot moving objects  it puts “action mode” on. Night mode sets your camera to use a longer shutter speed to help capture details. Movie mode extends you digital camera from capturing  images  to catch moving ones.  Aperture Priority mode (A or AV) is where you choose the aperture and your camera chooses the other settings. Program mode is similar to Auto but gives you a little more control over some other features including flash, white balance, ISO etc. Manual mode you have full control over your camera.