A matte painting is a painted representation of a landscape, set, or distant location that allows filmmakers to create the illusion of an environment that would otherwise be too expensive or impossible to build or visit. via wikipedia.

Yeah! Almost every background in series or movies today is the result of a digital matte paint to enhance the scenery. Don’t believe in what you see. Even series like Greys Anatomy or CIA live through a strong use of matte painting.