The
Unified Extensible Firmware Interface (
UEFI, pronounced as an initialism U-E-F-I or like "unify" without the
n) is a
specification that defines a software
interface between an
operating system and platform
firmware. UEFI replaces the Basic Input/Output System (
BIOS) firmware interface originally present in all
IBM PC-compatible personal computers, with most UEFI firmware implementations providing legacy support for BIOS services. UEFI can support remote diagnostics and repair of computers, even with no operating system installed.