A lightsaber is a fictional energy sword featured in the Star Wars universe. It consists of a hilt that emits a blade of plasma, which is contained within a magnetic field. Lightsabers are commonly associated with the Jedi and Sith, two opposing factions in the series, and are used in combat and defense. The color of a lightsaber's blade often signifies the user's affiliation or personality. For example, Jedi typically wield blue or green lightsabers, while Sith often use red ones. Lightsabers are iconic symbols of the Star Wars franchise and have become popular in various forms of media and merchandise.