Answer Description
UEFI (Unified Extensible Firmware Interface) is the next generation of BIOS. Technically it is not a new version or upgrade of BIOS but an entirely new solution. However as it does the same job, it is commonly referred to as a BIOS.
Wikipedia
The Unified Extensible Firmware Interface (UEFI) is a publicly available specification that defines a software interface between an operating system and platform firmware UEFI replaces the legacy Basic Input/Output System (BIOS) firmware interface originally present in all IBM PC-compatible personal computers, with most UEFI firmware implementations providing support for legacy BIOS services UEFI can support remote diagnostics and repair of computers, even with no operating system installedIntel developed the original Extensible Firmware Interface (EFI) specifications Some of the EFI's practices and data formats mirror those of Microsoft Windows In 2005, UEFI deprecated EFI 110 (the final release of EFI)
Unified_Extensible_Firmware_Interface - Wikipedia, the free encyclopedia