UEFI: Unified Extensible Firmware Interface
BIOS: Basic Input/output System
The advantages of UEFI
·
A powerful pre-boot environment capable of
running applications
·
Modular design
·
CPU-independent architecture (Itanium, x86,
x86-64, ARM Arch32, Arm Arch64)
·
BIOS interface compatibility and legacy
booting
·
The ability to boot from disks larger than 2TiB
(note the difference between 2TB and 2TiB)
MBR: Master Boot Record
GPT: GUID Partition Table
ESP: EFI System Partition
The
legacy BIOS systems are only able to boot from MBR partition tables
(there are exceptions, but this is generally a rule) and the MBR
specification can only address up to 2TiB of disk space, which results in
a BIOS system only being able to boot from disks of 2TiB or smaller.
Other
disadvantages of MBR formatted disks include a limited number of bootable
partitions and a single pointer to a bootloader/boot manager.
The GPT
specification allowed the disks of significantly larger size (several orders of
magnitude, up to Zettabytes in size) due to its larger bit allotment for
partition addressing, 64B instead of the 16B used by MBR. GPT can
partition disks of varying sizes depending on the sector size. This is due GPT
addressing sectors as opposed to individual bits or bytes.