Serial Attached SCSI (SAS) is a point-to-point serial protocol that moves data to and from computer-storage devices such as hard drives and tape drives. SAS replaces the older Parallel SCSI (Parallel Small Computer System Interface). The SAS interface uses the standard SCSI command set. SAS offers optional compatibility with Serial ATA (SATA), versions 2.0 and later. This also allows the connection of SATA drives to most SAS backplanes or controllers.