A storage area network (SAN) is any high-performance network whose primary purpose is to enable storage devices to communicate with computer systems and with each other. It doesn’t say that a SAN’s only purpose is communication between computers and storage. Many organizations operate perfectly viable SANs that carry occasional administrative and other application traffic. It doesn’t say that a SAN uses Fibre Channel or Ethernet or any other specific interconnect technology. A growing number of network technologies have architectural and physical properties that make them suitable for use in SANs. It doesn’t say what kind of storage devices are interconnected. Disk and tape drives, RAID subsystems, robotic libraries, and file servers are all being used productively in SAN environments today. One of the exciting aspects of SAN technology is that it is encouraging the development of new kinds of storage devices that provide new benefits to users. Some of these will undoubtedly fail in the market, but those that succeed will make lasting improvements in the way digital information is stored and processed. The beauty of SANs is that they connect a lot of storage devices to lot of servers and place in the administrator’s hands the choice of which server gets to access which storage devices.