Aperture

 Photo Taken at f2.8

Photo Taken at f32

1. We should relate aperture to our pupil because they work very similarly. 

2. The smaller the aperture the larger the f-stop, the larger the aperture the smaller the f-stop.

3. Aperture definitely affects depth of field because when the aperture is smaller it means that the depth of field is very large so almost everything is in focus. When the aperture is larger, the depth of field gets smaller and focuses only on the foreground objects.