Lighting

The lighting of a photo is very important it helps to decide what you see and how you interpret it, overrall the lighting can make or break a photo.

This photo is an image of singer Demi Lovato which was taken by Tyler Shields, the lighting used is a single white light focused on her face, however more lights in the background reveal the silhouette of her hat. The room itself is very dark and the photo is focused on the subjects face as it the most visible and well lit object and centred with a sharp focus. 

The following hyperlink will take you to a useful website that contains helpful information about lighting, it's particularly good because it suggests different ways in which you can use light: http://www.picturecorrect.com/tips/use-of-light-in-photography/.

The other example is quite different, although it is also of Demi Lovato and from the same shoot, because the subject is lit from the front with a centred, harsh, bright, white light. This means she has a sharp visible shadow. The photo is simple and lacks depth - except that which is added by the shadow.