Files with the .EFI extension contain the system data of devices based on Intel architecture – this includes both computers and devices such as AppleTV. EFI system files are used when communicating between the operating system and device-specific software, for example during the implementation of device driver updates, when loading the operating system, and when launching programs before booting the system.

Thanks to EFI files, it is possible to, for example, safely install device updates in a controlled environment during system boot, namely in the device’s EFI system partition. The EFI specification was created by Intel and standardized according to the UEFI standard, which stands for Unified Extensible Firmware Interface and is updated by the UEFI forum.