Camera modes P for program, the camera chooses the aperture and shutter for you, although there are a lot of cameras where you can still the aperture when you’re on Program A or Av for aperture (aperture value, canon) You change the aperture the camera chooses the shutter speed - you have control over the aperture so you can blur out the background (small Fstop numbers) or not blur out the background (big Fstop number ) Then Manual. You dial in the aperture you want - ie: if you want to blur out