UUID
also: Universally Unique Identifier
A UUID (Universally Unique Identifier) is a 128-bit number used to uniquely identify resources in Linux systems, most commonly disk partitions and filesystems. It remains the same even if the device name changes.
A UUID is a standardized identifier formatted as a 32-character hexadecimal string divided into five groups, typically displayed as 550e8400-e29b-41d4-a716-446655440000. Linux uses UUIDs to reliably reference storage devices and partitions independent of their device path (/dev/sda1, /dev/sdb1, etc.), which can change based on hardware detection order.
The primary advantage of UUIDs is reliability: if you physically rearrange disks or add new storage, your system can still find the correct partition because the UUID doesn't change. This is especially important for boot configurations and system mounts.
You can view UUIDs using commands like blkid, lsblk -o UUID, or by reading /etc/fstab, which typically references partitions by UUID rather than device name. For example: UUID=550e8400-e29b-41d4-a716-446655440000 /home ext4 defaults 0 2