It is a popular notion that in taking a photograph, the subject should always be lit from the front. In this usual setup, the light is coming from behind the photographer and the subject is facing the light source, such as the sun in outdoor settings, or an artificial light indoors.
Now if we talk about backlighting, it refers to lighting in a photograph that comes from behind an object. Because backlighting requires a subtle manipulation of a scene’s light, photographers consider it a more advanced technique to master. When effectively implemented in a scene, however, backlighting can enhance the finer details of an object (such as the tiny hairs on bug) or a scenes more delicate features (such as the dust particles or drops of mist in a given background).