: To use an ISO on a modified Xbox 360, it must be extracted using tools like WX360 to pull the game files into a folder structure that the console's custom dashboard can read.

ISO files are primarily used for archiving or for use on modified "JTAG" or "RGH" consoles.

In the context of the Gears of War franchise, a typically refers to a digital disk image of the Xbox 360 version of the game that has had its regional lockout (NTSC/PAL) removed or was originally published without it. Understanding "Region Free" for Gears of War

While many Xbox 360 games were locked to specific hardware regions, Microsoft-published titles like Gears of War are generally , meaning they can be played on any Xbox 360 console regardless of where it was purchased.