At its most basic, Rembrandt lighting consists of a single light source placed on a 45 degree offset from the subject, about 5 feet away. Positioned roughly two feet higher than eye level, the light source is angled slightly downward and hits the side of the face that is farthest away from the camera. 

Hard and soft light are different types of lighting that are commonly used in photography and filmmaking. Soft light is light that tends to "wrap" around objects, projecting diffused shadows with soft edges, whereas hard light is more focused and produces harsher shadows. 

Butterfly lighting is a lighting pattern used in portrait photography where the key light is placed above and pointing down on the subject's face. This creates a dramatic shadow under the nose and chin that looks like a butterfly. 

Backlighting means that you compose your pictures so that the primary light source is behind your subject. This can add a unique atmosphere to your photos while emphasising the subject. Backlight works as a dramatic effect that adds contrast and separates the subject from the background.

a small spot of light reflected from a shiny surface (as from an eye in portraiture or from metal or glass in photography) 

Shadows, deep blacks, and dark tones are all characteristics of low-key lighting. There are little to no whites and mid-tones. While more traditional lighting uses a three-point lighting setup with a key light, fill light and a backlight, low-key lighting uses mainly a key light. 

Shadows, deep blacks, and dark tones are all characteristics of low-key lighting. There are little to no whites and mid-tones. While more traditional lighting uses a three-point lighting setup with a key light, fill light and a backlight, low-key lighting uses mainly a key light.