My interpretation is that a "JBOD" is often an external drive enclosure that attaches to a server (or any compute device that can accommodate the connection (external SCSI, eSATA i.e.) This enclosure allows you to configure the drives as one or more than one RAID (redundant array of inexpensive disks). We use JBOD"S to extend the amount of storage a server or servers can access directly.
Scott Gorcester