The advice normally given to budding photographers is to have the light coming over the shoulder to shine on the subject head on. This gives bright clear images with no shadows. Very nice shots, but also very flat ones. With Contre-jour you CHUCK THAT ADVICE OUT!
Contre-jour (against the day) is shooting a photo when the main source of light is behind the subject (as opposed to behind the photographer). Another term for this is backlighting. This technique allows shadows to become an integral part of the composition, revealing texture and form. Backlighting can produce dramatic and intense images. The contrast in these shots are going to be much higher than normal. The background is brighter than the rest of the picture. Fill in lighting can be used to show detail in the subject (or increase exposure by one or two stops) . To produce a silhouette, expose for the background. This technique is a good way to give an impression of heat and brilliance. (as in an ocean scene when the glitter of sunlight bouncing off the water backlights a young child building sand castles on the beach)
Care has to be taken to avoid flare, extreme contrast and exposure reading errors.