While a light source from behind the camera helps you take sharp and colorful photographs, light from behind the subject may help you take pictures with spectacular highlights, especially when shot against darker backgrounds.

So, when you are taking photographs with the light source from behind the subject look out for the highlights on the subject —it may be on the hair of the person or on the dew drops on a leaf or flower, Make sure you notice it and capture it in your photograph! You may want to open up a stop or two to make the highlights even more spectacular and the shadows on the front of the subject a little lighter. (via Photography Tip Blog)