GUID Partition Table

The GUID Partition Table (GPT) is a standard for the layout of partition tables of a physical computer storage device, such as a hard disk drive or solid-state drive. It is part of the Unified Extensible Firmware Interface (UEFI) standard. It has several advantages over master boot record (MBR) partition tables, such as support for more than four primary partitions and 64-bit rather than 32-bit logical block addresses (LBA) for blocks on a storage device. The larger LBA size supports larger disks. Some BIOSes support GPT partition tables as well as MBR partition tables, in order to support larger disks than MBR partition tables can support. GPT uses universally unique identifiers (UUIDs), which are also known as globally unique identifiers (GUIDs), to identify partitions and partition types. All modern personal computer operating systems support GPT. Some, including macOS and Microsoft Windows on the x86 architecture, support booting from GPT partitions only on systems with EFI firmware, but FreeBSD and most Linux distributions can boot from GPT partitions on systems with either the BIOS or the EFI firmware interface.