Final answer:
The term for illuminating something from behind is called 'backlight' or 'backlit', which can create a silhouette effect. To balance a too-dark subject from strong backlight, photographers use a 'fill flash' technique.
Step-by-step explanation:
The term for illuminating something from behind is called backlight or backlit. When light comes from behind the subject, it creates a dramatic effect by making the subject appear as a dark shape against the brighter background, often creating a silhouette. However, when backlight is too strong and causes the subject to appear too dark, a photographic technique called fill flash can be used to balance the exposure. This adds light to the front of the subject, combining the natural backlight with the light from the camera's flash.