disk identifier (guid)

When I fire up command : `gdisk /dev/nvme0`, and input `p`, I got these: ``` Disk /dev/nvme0n1: 500118192 sectors, 238.5 GiB Logical sector size: 512 bytes Disk identifier (GUID): E37EBCC8-2251-420B-B2A6-3B515E3D2892 Partition table holds up to 128 entries First usable sector is 34, last usable...