Film editing is both a creative and a technical part of the post-production process of filmmaking. The term is derived from the traditional process of working with film which increasingly involves the use of digital technology. When putting together some sort of video composition, typically, you would need a collection of shots and footages that vary from one another. The act of adjusting the shots you have already taken, and turning them into something new is known as film editing.
The film editor works with raw footage, selecting shots and combining them into sequences which create a finished motion picture.