SAN: short for storage area network, SAN is a high-speed network of storage devices that also connects those storage devices with servers. It provides block-level storage that can be accessed by the applications running on any networked servers. SAN storage devices can include tape libraries and disk-based devices, like RAID hardware.

The main functions of a storage area network (SAN) includes the following:

• A high-speed network of storage devices.
• Connects the storage devices with servers.
• Can be accessed by applications on networked servers.
• Particularly helpful in backup and disaster recovery.
• Uses networking protocols to span longer distances geographically.
• SAN can also simplify some management tasks.
• Offers flexibility, availability and performance.

SAN commonly utilizes Fiber Channel interconnections,  and include databases, server clustering, messaging applications, and high I/O, transaction-intensive apps.