Pictorial lighting is a term used to describe a lighting setup that is controlled and manipulated to produce the desired appealing effects. This type of lighting is far from natural and would not be used when undertaking wildlife or documentary work. It is typically used for studio portraiture where every aspect of setup, lighting and background is designed to produce the best possible "likeness" of a person. Subjects usually want to see themselves looking at their best, and have no problems with a photographer using lighting to conceal blemishes, enhance the appearance of hair etc.
Studio photographers use continuous tungsten lighting of studio flash to create the desired lighting effects. Tungsten sources can be uncomfortable for a model because they dissipate a lot of heat, but their continuous output allows a photographer to see the combined effect created by the various lights. With flash sources it is more difficult to anticipate the effect produced by multiple sources but in the digital era this is less important because images can be inspected immediately and any necessary adjustments made.
Studio pictorial lighting is typically achieved using three lights. A main key light is might be positioned about 30 - 45 degrees to one side of the camera-to-subject line and a fill-in light, usually set to a lower output level, is used to soften shadows cast by the main light. A back light might typically be used to separate the subject from the background or to light the hair.