It allows the game to communicate with Steam's servers, often by "spoofing" the game as a free-to-play title (like Spacewar or Cube Racer ) so you can invite friends through the Steam overlay.
It ensures that your game version matches the "Fix" version so that servers are visible in the lobby browser. Safety & Usage Notes EtAHN_Fix_Repair_Steam_Generic.rar
Usually, you extract the contents of this .rar directly into the game's main folder (where the .exe is located), replacing any existing files when prompted. It allows the game to communicate with Steam's