Close Up Shot:-
A close up shot is very good at showing the fine details of something. In this example it shows the emotion of happiness. You can clearly see the wide smile and the emotion through the eyes. In addition to this, you can see the position of the shoulders which are at a slight angle which suggests excitement as well.
Medium Shot:-
A medium shot not only shows facial expressions but also body posture and actions. This example shows a funny example where you can still see a smirk on the face but you can also see that the subjects posture which is slightly crouched and holding up the arms. This is useful to show a bigger picture than a close up shot.
Long Shot:-
A long shot shows the whole person in the frame. This shows everything that the person is doing so can reveal more than a medium shot. In this shot, you can see the subject is slouched over which implies boredom and tiredness. This is further shown through the lack of facial expressions. A long shot also shows the persons feet which can reveal whether they are planted and stationary or positioned as if they are about to move, creating action.