Halo, originally created by Bungie and is currently managed and produced by 343 Industries, a division of Microsoft’s Xbox Game Studios. Halo is a military science fiction media brand.
The franchise, which primarily takes place in the 26th century, is focused on wars between various alien species and mankind.
The titular Halos are enormous ring-shaped superweapons built by the Forerunners to eliminate the parasitic Flood, but the Covenant mistake them for transcendental holy objects.
Why did Bungie stop making halos?
Because, currently, Microsoft owns the rights to the Halo brand. Bungie developed the first several games and originated the Halo franchise. The first Halo was developed by Bungie when Microsoft acquired the studio in 1997, acquiring the IP at the same time.
Microsoft kept the rights to Halo after Bungie left the company in 2007, establishing the in-house studio 343 Industries to take over the successful franchise. Halo’s prospects of arriving on PlayStation are currently as remote as they were before Sony acquired Bungie.