Forerunners are ancient, advanced beings in the fictional universe of Halo. They are known for their remarkable technology and architecture, which includes massive structures like the Halo rings. The Forerunners played a crucial role in the galaxy's history, particularly in their conflict with the parasitic Flood. The Forerunners are often depicted as protectors of the galaxy, having created the Halo Array as a means to combat the Flood threat. Their legacy is evident in the remnants of their civilization, which continue to influence events in the Halo series, shaping the lives of various species, including humans and Covenant.