Computer-generated imagery (CGI) is the application of computer graphics to create or contribute to images in art, printed media, video games, simulators, computer animation and VFX in films, television programs, shorts, commercials, and videos. The images may be dynamic or static, and may be two-dimensional (2D), although the term "CGI" is most commonly used to refer to the 3-D computer graphics used for creating characters, scenes and special effects in films and television, which is described as "CGI animation".

The first feature film to make use of CGI was the 1973 movie Westworld. Other early films that incorporated CGI include Star Wars (1977), Tron (1982), The Last Starfighter (1984), Young Sherlock Holmes (1985) and Flight of the Navigator (1986). The first music video to use CGI was Dire Straits' award-winning "Money for Nothing" (1985), whose success was instrumental in giving the process mainstream exposure.

The evolution of CGI led to the emergence of virtual cinematography in the 1990s, where the vision of the simulated camera is not constrained by the laws of physics. Availability of CGI software and increased computer speeds have allowed individual artists and small companies to produce professional-grade films, games, and fine art from their home computers.

The term virtual world refers to agent-based, interactive environments, which are now created with CGI.

 

Note:   The above text is excerpted from the Wikipedia article Computer-generated imagery, which has been released under the GNU Free Documentation License.