With the advent of iSCSI as the standard for networked storage, businesses can leverage existing skills and network infrastructure to create Ethernet-based SANs that deliver the performance of Fibre Channel--but at a fraction of the cost. iSCSI enables block-level data to be transported between a server and a storage device over an IP network. An iSCSI initiator is hardware or software that runs on a host and initiates I/O to an iSCSI target, which is a storage device (usually, a logical volume) that responds to read/write requests.

Upon connection, an iSCSI initiator and iSCSI target authenticate each other. After login, the target is seen as a local device that can be used like any other SCSI disk. When accessing data, all initiators run at line speed.