Cloud services like Microsoft SkyDrive are all the rage, but many enterprises and home-based digital packrats would rather store files locally. Windows 8 has a new feature called Storage Spaces that lets you to save files to two or more drives. So if one drive fails, your files are safe. If you run low on capacity, you can add more drives to a "storage pool" of drives.
Pooled disks are connected via USB, SATA (Serial ATA), or SAS (Serial Attached SCSI). Microsoft uses a technology called thin provisioning to expand the storage capacity of physical disks beyond their stated size. A storage pool of two 2-TB hard disks (4 TB), for instance, will become a 10-TB mirrored space. For more details, read Microsoft's detailed overview of how Storage Spaces works.