GPT disk partition: data structures

Systems with EFI use not only DOS partition system but also the GUID Partition Table (GPT). GPT disks are more reliable, support up to separate 128 partitions and use 64 bit LBA addressing.

Library: UEFI GUIDs

GUID: The 128-bit Globally Unique IDentifier (GUID) for the protocol interface.
Protocols in UEFI are named using GUID (Globally Unique IDentifier).
Each UEFI protocol must have a unique GUID.