storage: A number from zero to seven that identifies each device connected via their SCSI ports. The Mac itself is seven, and internal hard drives are usually zero. The ID is also called the SCSI address.
The number assigned to a SCSI component that the SCSI controller uses for identification.
A unique identification for each SCSI device on the SCSI bus. Each SCSI bus has fifteen available SCSI IDs numbered 0 through 15 for Wide SCSI or 0-7 for 8-bit SCSI. The host bus adapter is usually assigned ID 7, which gives it priority to control the bus.