Three pillars aperture, shutter speed, ISO

Aperture

 F2.8

F16

1. Our eye and pupil.
2. The smaller the aperture the less light and blurs out the background, the higher the aperture the more light and the background hardly blurs out.
3. It focus on the main object and really blurs out the background.

                                                   Shutter Speed

 High shutter speed

 Slow shutter speed

a.) fast shutter speed                                      a.) medium shutter speed

b.) medium shutter speed                              b.) slow shutter speed

c.) slow shutter speed                                    c.) slow shutter speed

d.) slow shutter speed                                    d.) slow shutter speed

e.) slow shutter speed                                    e.) slow shutter speed

f.) fast shutter speed                                       f.) medium shutter speed 

Aperture priority - you set up the aperture and the shutter speed is automatically.
Shutter priority - the aperture is automatically and you have to choose the shutter speed.
Manual - shutter speed and aperture is automatic.

 6400 iso

 200 iso

1. You can capture the movement without blur.

2. When there is plenty of light use low iso.

3.