What is SAN?
SAN is a network-based storage solution. A SAN typically uses Fibre Channel connectivity. A SAN stores data at the block level. To a client OS, a SAN typically appears as a disk i.e. SAN-connected disks appear to the user as local drives.
SAN uses multiple storage appliances to create a consolidated shared pool of storage which is accessible to servers and user-groups using iSCSI and/or Fibre Channel protocols.