UEFI (Unified Extensible Firmware Interface) is a standard firmware interface for PCs, designed to replace BIOS (basic input/output system). This standard was created by over 140 technology companies as part of the UEFI consortium, including Microsoft. It's designed to improve software interoperability and address limitations of BIOS. Some advantages of UEFI firmware include:
Better security by helping to protect the pre-startup—or pre-boot—process against bootkit attacks.
Faster startup times and resuming from hibernation.
Support for drives larger than 2.2 terabytes (TB).
Support for modern, 64-bit firmware device drivers that the system can use to address more than 17.2 billion gigabytes (GB) of memory during startup.
Capabililty to use BIOS with UEFI hardware.
All 64-bit versions of PCs running Windows with a logo from the Windows Certification Program will use UEFI instead of BIOS. To learn more about your PC's support of UEFI, refer to documentation that came with your PC.