Visual Effects (or Computer Generated Imagery) is the marriage of art and technology to support and enhance storytelling in Feature Films, Shorts, Animation, Stop-Motion, TV, Commercials, Music Videos as well as other industries looking for ways to augment their content, such as the military or health field.
It is the process by which imagery is fabricated and/or manipulated and then blended seamlessly with live-action footage to create a single shot or series of shots to build an entire scene.
The bulk of VFX work happens towards the end of a production schedule and continues after as part of post-production. However, based on the scope or requirements of a project, it can often start much earlier as part of pre-production in order to carefully choreograph and work in close partnership with the live-action shoot. This not only ensures the success of the final product, but can also provide invaluable information to the client, the film crew, the director and actors who may find themselves in need of guidance or parameters that do not physically exist.