The 3 settings determine camera exposure are the Aperture, ISO and Shutter Speed.

 

Aperture controls the area over which light can enter your camera. The size of the lens opening and it controls the amount of light let in. So the larger aperture lets in more light while a smaller aperture lets in less light.

ISO controls the sensitivity of your camera’s sensor to a given amount of light. The lower the ISO rating, the less sensitive the image sensor is and therefore the smoother the image, because there is less digital noise in the image.

Shutter Speed controls how long light enters the lens and hits the image sensor or film plane.Fast shutter speed seems like freeze action while slow shutter speed seems like silky flowing water.

Explanation

Aperture  determines the depth of the field

ISO – The higher the ISO rating the stronger the image sensor has to work to establish an effective image, which thereby produces more digital noise

Shutter Speed – If the shutter speed is slower, then you’ll get blurred objects.