Real (physical) and virtual printers

A real (physical) printer is the printer hardware attached to the system via a serial or parallel port, or through a network connection such as a network terminal server.

When the real printer is attached via a serial or parallel port local to the system, the printer device driver in the kernel communicates with the printer hardware and provides an interface between the printer hardware and a virtual printer.

A virtual printer is a set of attributes and their associated values that define a high-level data stream (such as ASCII or Postscript) and the methods for processing that data stream. This does not include information about how the real printer is attached to the host computer or about the protocol used for transferring bytes of data to and from the real printer. The piobe backend uses information stored in the virtual printer definition to control print job processing. The physical storage medium of the sets of attributes and their associated values is called a printer colon file.