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.
The goal is to write the USB storage class driver as a block device driver that plugs into an appropriate file system driver at the upper edge so that applications can use it seamlessly. The USB storage class driver can support multiple USB storage devices connected to the Windows Embedded CE OS. The storage driver exposes the stream interface. For more information, see Stream Interface Drivers.