It’s a network of devices (can include tape drives and raid disk arrays, among others) all working together to provide an excellent block level storage. In a storage network, a server issues a request for specific blocks, or data segments, from specific disk drives. This method is known as block storage. SAN storage appears to the server as its own storage device and is best suited for high performance database storage and e-mail storage, among others. SAN uses fiber channel as the primary media with SCSI being the main input/output (I/O) protocol.