Storage Area Network (SAN):    1. A network whose primary purpose is the transfer of data between computer systems and storage elements and among storage elements. A SAN consists of a communication infrastructure, which provides physical connections, and a management layer, which organizes the connections, storage elements, and computer systems so that data transfer is secure and robust. The term SAN is usually (but not necessarily) identified with block I/O services rather than file access services.    2. A storage system consisting of storage elements, storage devices, computer systems, and/or appliances, plus all control software, communicating over a network.
 

See also: iSCSI SAN, fabric, FC SAN

Note: The definition does not identify the term SAN with Fibre Channel technology. It is encouraged that when the term SAN is used in connection with Fibre Channel technology, to use a qualified phrase such as "Fibre Channel SAN.". According to this definition an Ethernet-based network whose primary purpose is to provide access to storage elements would be considered a SAN. SANs are sometimes also used for system interconnection in clusters.