What is the purpose of "System ID" field in vgdisplay output?

Issue

• What is the purpose of "System ID" field in vgdisplay output?
• How I can use it? Can I set it?

[root@localhost ~]# vgdisplay testVG
  --- Volume group ---
  VG Name               testVG
  System ID
  Format                lvm2
  Metadata Areas        1
  Metadata Sequence No  21
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                6
  Open LV               6
  Max PV                0
  Cur PV                1
  Act PV                1
  VG Size               112.18 GiB
  PE Size               4.00 MiB
  Total PE              28719
  Alloc PE / Size       28594 / 111.70 GiB
  Free  PE / Size       125 / 500.00 MiB
  VG UUID               MYlhWY-OZo1-Tprj-s6L2-m8u0-IA4w-tIotjA