Forerunner
From Halopedia, the Halo wiki
Summary
The "Forerunners" is the translated Covenant name for the race that built Halo. It is theorized that this same race is responsible for the artifact that was found on Reach, and on Sigma Octanus VI.
The artifacts appear to have originated on different worlds, but have somehow made it onto these other planets. These artifacts are our only means of finding information about the Forerunner.
