The term you're looking for is aspect ratio. That particular example looks to be cropped (in post) to 2.35:1, aka cinemascope.
There are a couple ways to accomplish this. First would be to shoot with anamorphic lenses, which will compress the wider image into the narrower sensor size, this is then either stretched back out in post, or in the case of film/digital production, projected through a similar anamorphic lens to stretch it back out onto the projection screen.
That particular example, given that it was shot on a black magic pocket camera, with a 20mm lens, and no mention of anamorphics, was simply resized and cropped in post.
