In-universe

The term "in-universe" is used to describe details that exist within the fictional world of Star Wars, differentiating it from "out-of-universe" information, which pertains to the real world. For example, the explanation within the Star Wars narrative for Han Solo's chin scar is a brawl with a knife-wielding criminal on Dellalt. However, the real-world explanation is that Harrison Ford, the actor who played Han Solo, has a chin scar resulting from a car accident.

Furthermore, "in-universe" also applies to works presented as if they were authored by individuals living inside the Star Wars universe. These in-universe materials often include sourcebooks intended for a general audience, such as The Essential Guide to Alien Species, or roleplaying game supplements like The Thrawn Trilogy Sourcebook and Platt's Smugglers Guide. To maintain the illusion of being created within the Star Wars universe, these works avoid mentioning Star Wars as a movie franchise or media property, ignore information from later points in the timeline than when the books are supposedly written, and frequently attribute the work to a fictional "author" within the universe.