Computer animation is the art of creating moving images via the use of computers. It is a subfield of computer graphics and animation. Increasingly it is created by means of 3D computer graphics, though 2D computer graphics are still widely used for low bandwidth and faster real-time rendering needs.
Sometimes the target of the animation is the computer itself, but it sometimes the target is another medium, such as film.
It is also referred to as CGI (Computer-generated imagery or computer-generated imaging), especially when used in films. To create the illusion of movement, an image is displayed on the computer screen then quickly replaced by a new image that is similar to the previous image, but shifted slightly.
This technique is identical to how the illusion of movement is achieved with television and motion pictures. Computer animation is essentially a digital successor to the art of stop motion animation of 3D models and frame-by-frame animation of 2D illustrations.