Definition: Match moving is primarily used to track the movement of a camera through a shot so that an identical virtual camera move can be reproduced in a 3D animation program. - Wikipedia
Matchmoving, also known as video tracking or video matching, is the photogrammetric process in which computer generated objects are placed within a video background.
Placing computer generated vehicles or objects into video results in highly realistic animations. In many cases, this technique is so compelling that it appears as though video was taken while the accident happened.
In addition to its uses in animation, matchmoving has proven to be a valuable tool for extracting 3D data from video. This data can be used to help determine distances and relationships between objects in the scene.