A line is a concept in Western comic books which denotes a specific group of publications by a publisher.
Sometimes taking place in a separate continuity or more loose continuity (such as Vertigo by DC Comics) or exploring a kind of subject matter and or genre which the publisher does not want to involve in their main franchise or so called "universe".
Dark Horse Comics has several lines which focuses on their licensed film properties such as Alien, Predator and Star Wars.
The Aliens line consists only of limited series, one-shots and graphic novels due to the publisher's wish to allow artistic freedom.
[3][4] Dark Horse also publishes a line of comics which are creator owned but are connected through common oversight by editor Karen Berger.