Firmware

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Apple TV
There has always been a big confusion about the firmware versions of the Apple TV (2nd generation), because the version numbers don't match the version number that is being displayed.

Here's an overview. The best way to refer to a specific firmware is to use the build number.

The "Internal" version and build numbers refer to the "ProductVersion" and "ProductBuildVersion" keys in the IPSW's BuildManifest.plist.

The "Marketing" version and build numbers are what is reported on the Apple TV's About screen.