A "green screen" refers to a large green background used in movies or videos. It allows filmmakers to replace the green color with different scenes, graphics, or special effects during editing. Full definition
As someone who has stated a preference for location shooting, how does making special effects movies that require a lot of green screen shooting change your approach? (movieweb.com)
I really just love that the film created this world with sets instead of using green screens. (allgeektome.net)
It also shows how the effects landscape has changed as so many of the backgrounds were done with green screen that could be looked at live as the film was being shot. (collider.com)