Aperture Control

5.6
From this it is clear that the background of the image is out of focus and slightly blurred and the subject in the foreground is being focused on and more defined.

15
This image shows the aperture at 15. This shows that neither the background or foreground is being focused on and they are both of equal detail and focus.

36
This image shows a high aperture setting and it is apparent that the background is more defined and has more detail, whereas the foreground objects are slightly out of focus and blurred.