The Halo franchise is a series of science fiction games and media centered around the conflict between humanity and various alien races. The games, beginning with Halo: Combat Evolved, follow the story of the super-soldier Master Chief and his AI companion, Cortana, as they fight to protect humanity from threats like the Covenant and the parasitic Flood. The series is known for its engaging storylines, innovative gameplay, and extensive lore, including novels, comics, and an animated anthology called Halo Legends.

Beyond the games, Halo has had a significant cultural impact, with its protagonist, Master Chief, becoming an iconic figure in gaming. The franchise has expanded into various media, including novels, comics, and animated series, enriching its universe and exploring new facets of its lore. It has also influenced other first-person shooters and has been credited with popularizing online multiplayer gaming on consoles. Fans can find a wide range of merchandise, toys, figures, and collectibles that reflect the series' popularity and enduring legacy.