Side lighting

Definition: 

The main light source in side lighting comes from one side of the screen. 

Uses: 

Side lighting is used to light one side of a character's face or to cast shadows across specific elements of the set. 

It can be used to create mystery, intrigue or conspiracy. 

Side lighting creates a sense of a dark side and a light side of a character, thus casting the motives or actions of a character in doubt.