Definition:
Some things cannot be built. Others are too dangerous, too expensive, or simply do not exist. Visual effects, abbreviated VFX, are the use of digital tools in post-production to create, enhance, or alter visual elements in ways that were not captured or could not have been captured by the camera during filming.
What It Means in Movies:
VFX encompasses everything from digital creatures and constructed environments to subtle wire removal, sky replacement, and crowd augmentation. A fantasy film may require thousands of fully digital shots. A period drama may require only a handful of invisible fixes. Both are VFX. The difference is only in scale and visibility.
Why It Matters:
VFX has fundamentally expanded the visual possibilities of cinema. Stories that were impossible to put on screen are now achievable. James Cameron's Avatar built the entire world of Pandora through VFX, setting a new benchmark for what photorealistic digital environments could achieve at scale.
Example:
A production finishing principal photography has thousands of raw shots, some requiring complete digital environments, others requiring only invisible fixes. VFX post-production takes all of that raw material and, over months of work, delivers the finished frames the editor needs to complete the cut.