Definition
In 3D computer graphics, it often happens that a well-modeled 3D object can look unconvincing, flat, expressionless, or even plastic because of the badly implemented lighting solution. On the other hand, well-chosen lighting techniques can significantly enhance the project value.
3D lighting is the combination of techniques that are utilized to project light in a 3D environment. The lighting artists responsible for 3D lighting in animation can choose from a range of light sources, techniques, effects, and tools that suit the needs and mood of the scene.
3D lighting holds as much importance as the lighting in photography and videography. The artist responsible for lighting in the animation will place specific light sources in a way that they draw attention to a particular part of the animation. 
Uses of 3D Lighting in Animation
In 3D animation, lighting is often used to relay the emotion of the scene, which time and part of the day it is, the weather at that particular point in time, the location of the scene, and it also supports the story for the audience to get a better understanding. For example, a yellow light could signify a bright, sunny day.
3D commercials, 3D animations, and product visualizations, etc. also make use of 3D lighting by making the objects look appealing or boring by constantly altering the intensity and color of the lights. With the help of 3D lighting, shades, reflections and shadows are created in a 3D animation. This is very much like how lighting is used in a live-action set. The main difference however between the two is that lighting artists in animation have more freedom to be creative as they are not governed by the physics and properties of actual light.
Additional information
Global Illumination (GI) and Skydome are more commonly used algorithms that are used to add 3D lighting in a scene in animation studios. In addition to that, different types of light sources are used to add lighting in a scene in combination with Global Illumination (GI) and Skydome. Experimenting with various light sources and their intensity can allow you to replicate life-like lighting in a virtual world. These light sources include Directional Light, Point Light, Area Light, and Spotlight.
