SCSI, FC SAN, iSCSI SAN, WWN, WWNN, WWPN, IQN

SCSI - Small Computer System Interface

FC SAN - Fiber Channel which dedicatedly transfers SCSI protocol.

iSCSI SAN - A protocol transfers SCSI within TCP packets.

To uniquely identify a node in SAN, FC uses WWNN (worldwide node name ) and WWPN (worldwide Port Name), while iSCSI uses IQN (internet qualified name).

A unique name (be it wwn or iqn) is critical for multipath handling. This name keeps consistent regardless of the path between the host and the storage.