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.
Hardware is best described as a device, such as a hard drive, that is physically connected to the computer or something that can be physically touched. A CD-ROM, computer display monitor, printer, and video card are all examples of computer hardware.