View full size image. Measured by surface area, the Caspian Sea is the world's largest inland water body. The sea covers roughly 143,200 square miles (371,000 square kilometers) and borders five countries: Iran, Russia, Kazakhstan, Turkmenistan and Azerbaijan.
A logical device driver is a high level abstraction of how a device behaves. A physical device driver is a driver for a specific piece of hardware. The logical device driver talks to the physical device driver for you to keep you abstracted from the underlying hardware. For example, there are many different types of printers, and they typically come with their own drivers.
To view the physical device identifiers (like for a hard drive, not to be confused with a disk's partitions), the command: produces an output similar to: Note that each partition (called part#) identifies with their parent device-this is because they exist on that physical piece of hardware. You will also notice that the drives and partitions appear twice, the first time as ata and the second time as scsi. I am unclear as to why this is, but I believe it is related to IDE hard drives being identified to the system as SCSI drives (because of ide-scsi emulation?).