SCSI and SAS
SCSI (pronounced "scuzzy") stands for Small Computer System Interface, but much like most acronyms, knowing the words that make it up doesn't give you any insight into what the technology actually does. For years, SCSI has been the chosen storage device type for servers. SCSI actually refers to the interface that is used between the server and the storage device, but most people refer to a drive with a SCSI interface as simply a SCSI drive.
SCSI was initially adopted as a standard interface for server devices because of its ability to connect multiple devices (up to 16) through one interface. The technology was improved upon over the years, leading to faster speeds, larger buses (paths that data being transferred uses). However, the traditional SCSI technology (having progressed to the SCSI-3 standard) wasn't keeping up with the serial technologies being developed for the lowly PC systems, like SATA, which boasts a 3Gb/sec transfer rate.
Enter SAS, which is actually an acronym that contains an acronym, standing for Serial Attached SCSI. In 2009, the SAS standard will be released allowing for transfer rates of up to 6Gb/sec - two times that of comparable PC components. This will allow the fast accessing, copying, and transferring of data from servers to clients, other drives, or backup systems.