as more and more computers adopt the "UEFI BIOS",just write the focus, UEFI Full Name "Unified Extensible Firmware Interface",relative to "Legacy BIOS"(Traditional BIOS ) has more advantages: Modular Design,graphical interface, enhanced compatibility and extensibility.
The Legacy BIOS reads the primary boot record "MBR" of the disk, which in turn reads the "Boot file" of the last Windows system; UEFI The BIOS automatically reads the executable program (EFI format) under a specific partition of fat format (typically ESP partition), and the EFI file looks for the Windows BCD boot menu to enter the system (abbreviated process) .
Under the UEFI BIOS, we can manually select the "EFI file" under the FAT partition and then do the related operations (similar to the DOS Toolbox), or you can manually select the EFI files needed to boot the Windows system to enter the system.
Note: EFI is usually synonymous with UEFI when it is used. EFI refers to the Extensible Firmware Interface, which is the predecessor of UEFI.
Next-generation UEFI BIOS Uefi Basics Introduction (1)