The relationship between SCSI devices is described by a client-server service-delivery model.

Note that the "world" may only consist of a very small number of SCSI devices.

SCSI devices usually connect to a controller card like this one.

It allows systems with a slow bus or simple systems to also use SCSI devices.

Up to eight SCSI devices, numbered 0 to 7, can be daisy-chained.

Most of the common SCSI devices such as disk-drives support only one or two diagnostic pages.

The range limitations of the data cable allows for external SCSI devices.

A SCSI device attaches to the bus but does not interrupt it.

Specific types of connectors for parallel SCSI devices were developed by vendors over time.

Both narrow and wide SCSI devices can be attached to the same parallel bus.