Short answers, pulled from the story.
Motion capture is the process of recording high-resolution movement of actors or objects into a computer system, then mapping that movement data onto digital character models. In films it has been used to create characters such as Gollum in The Lord of the Rings, Jar Jar Binks in Star Wars: Episode I, and the Na'vi in Avatar.
The 2000 Indian-American film Sinbad: Beyond the Veil of Mists was the first feature-length film made primarily with motion capture, though it had a very limited release. The 2001 film Final Fantasy: The Spirits Within was the first widely released feature film built on the technology.
Didier Pourcel and his team at Gribouille produced the first virtual actor animated by motion capture in 1993. The project involved cloning the body and face of French comedian Richard Bohringer using what Pourcel described as still-nascent motion capture tools.
Motion capture was used in video games as early as 1988, in Martech's Vixen (with movements performed by model Corinne Russell) and Magical Company's Last Apostle Puppet Show. Sega later used it to animate the 3D character models in Virtua Fighter in 1993 and Virtua Fighter 2 in 1994.
Performance capture is a term used when motion capture also includes recording facial expressions, finger movements, and subtle emotional cues, in addition to full-body movement. The distinction is most relevant in film, where performance capture is used to convey a fuller range of an actor's live work.
Purdue University's Purdue UAS Research and Test facility houses the world's largest indoor motion capture system, using 60 cameras to cover 600,000 cubic feet. The system tracks targets with millimeter accuracy, providing a ground-truth position baseline that researchers use to evaluate drone control, estimation, and perception algorithms in an indoor environment where outdoor flight regulations do not apply.