Volume Set is a single volume created using discontiguous free areas on hard disks. By using the Microsoft Windows NT administrative tool Disk Administrator, you can create volume sets by combining between 2 and 32 free areas on your disk drives.
Volume sets are called spanned volumes in Microsoft Windows 2000, and they are created using the Computer Management snap-in for the Microsoft Management Console (MMC).
The Windows NT system partition and boot partition cannot be volume sets.
You can extend a volume set formatted with the NTFS file system without having to reformat the entire volume.