uefi EFI files, most commonly referred to as, Extensible Firmware Interface files, are a type of file extension most commonly used for creating an environment in order to boot up the OS. EFI file extensions are usually hidden in the OS in a special EFI system partition and are considered to be UEFI boot loaders. EFI files exist in UEFI file systems and contain data which dictates, how the boot process should occur, or how the booting phases should be executed/initiated. The EFI format was originally developed in the 1990s when the first generation of the Intel HP Itanium systems were being built. It was designed as part of the "Intel Boot Initiative" to tackle server platforms which were large in size; later on, it came to be known as the "Extensible Firmware Interface (EFI)"
tar The .tar filename was originally designed to be used as a TApe ARchiver to store entire file systems and files as single files on tape storage medium. It was designed by AT&T in 1979. Today, the format more commonly refers to an archive or collation of multiple files into a single file with the .tar filename extension. The format is an open source file archive format commonly associated with the UNIX tar command however other data compression tools are capable of effectively compressing and/or decompressing files saved with the .tar file format. Doing so typically adds the compression filename extension to the archive file for example .tar.bz2.