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.
Drivers are the piece of software that tells your computer how to talk to the specific hardware you have installed or connected to your computer. The drivers must be specific to the particular model of your computer or sound device, and are usually produced by the sound device or motherboard manufacturer.