SAS– Serial Attached SCSI (SAS) is a computer bus technology designed primarily for transfer of data to and from devices like CD-ROM drives, hard drives, and so on.SAS is a serial communication protocol for direct attached storage (DAS) devices. It is designed as a replacement for the parallel SCSIin the corporate and enterprise market, allowing for much higher speed data transfers than ever before, and is backwards-compatible with SATA drives. SAS uses serial communication instead of the parallel method found in traditional SCSI devices, however, SCSI commands are still utilized for interacting with SAS End devices.