the Basic Input Output System (BIOS) has been the firmware loaded on most desktop and laptop computers. However, since 2005 the Unified Extensible Firmware Interface (UEFI) has gained in popularity to the point where in 2014 it became the predominant type of firmware shipped with motherboards. UEFI is often pronounced similar to “unify” or the acronym is simply spelled out: U-E-F-I. But many technicians (and even some manufacturers) will still just refer to it as “BIOS” or possibly as “UEFI BIOS.” For the most part in this chapter, the two terms “BIOS” and UEFI” can be used interchangeably. For simplicity during the course of the book, I often refer to a motherboard’s firmware simply as BIOS.