Before Steam and the Definitive Edition, scene release groups ruled the warez world. RexaGames was a prominent "repacker" in the mid-2000s. Their specific .rar archive of GTA San Andreas was popular because it was highly compressed (fitting a 4.7GB DVD onto a few CDs) and often came pre-cracked.
Grand Theft Auto: San Andreas content from Rexa Games typically refers to a pre-configured, compressed RAR file grand theft auto san andreas rexagamescomrar fixed
This particular version represents a community-driven effort to ensure that one of the greatest games of all time remains playable on modern hardware while maintaining the integrity of the original experience. Why Players Seek Fixed Archive Versions Before Steam and the Definitive Edition, scene release
Actionable checklist before using a “fixed” archive: Before Steam and the Definitive Edition