How would you define how iSCSI works in layman's terms?

Information that is key to modern business is ultimately stored on disk in the form of blocks of data. That block data is written to and read from disk using the SCSI protocol, which is optimized for low-overhead movement of data from disks to file servers, application servers or workstations. The iSCSI protocol carries those SCSI commands for reads and writes of data to disk using TCP/IP, which has become the Esperanto of data communications. By using TCP/IP, iSCSI enables host computer systems, storage arrays and tape libraries to be plugged into a mainstream IP network. Data can now be stored and retrieved at very high speed and with high reliability over common network infrastructures and block data transport can be managed with established IP network management tools. In an iSCSI configuration, a host system would have a Gigabit Ethernet card as the interface to the IP network. iSCSI can be run in software over a traditional GE NIC, although much better performance is gained by ... more