The 3 Pillars of Photography

Aperture

    You should closely relate aperture to the pupil in your eye, because they both control how much comes in your eye/lens. The smaller the aperture the more light let in, the larger the aperture the less light let in. That is what makes aperture confusing for so many people. A large f-number (f-number is a measurement of aperture) will make the foreground clear and the background blurry. A small f-number will make the foreground focused again but the background much clearer compared to a larger f-number.

Examples:

The left is at f2.8, the right at f14

Shutter Speed

    When the day has reasonable light:
a) high
b) low
c) high
d) high
e) low
f) high

    When the sun has gone down and you can't see one end of the courtyard to the other:
a) high
b) low
c) high
d) low
e) low
f) high

    In aperture priority mode, the camera chooses your shutter speed and you set the aperture. In Shutter priority mode, you set the shutter speed and the camera sets the aperture. In manual mode, you set both the aperture and shutter speed.

Picture with high shutter speed

Picture with slow shutter speed

ISO   

    The advantages of shooting at a higher ISO at a sports game is that it helps to freeze motion, which reduces the need for higher shutter speed. The author said to stick to a low ISO whenever possible, to keep the quality of the photo. Also, he said you might want to use lower ISO in dim and dark environments. You want to increase the ISO when there is not enough light to capture an image quickly, or when you want to get ultra-fast shots.

Example of ISO difference:

As you can see, the higher ISO is grainier, or has more "sound"