I guess it means the physical printer would not be installed in system..instead an application will take care of print previews and convert the document in printable form...When print button is clicked a virtual printer driver will come into action and the document is converted to printable form...If you want to know about virtual printer see the link:- http://en.wikipedia.org/wiki/Virtual_printer
A virtual printer is a computer software whose user interface and API resemble that of a printer driver and instead of having the document printed on paper, the particular software would process its contents in some other way, often resulting in a file being produced or the information being transmitted.
Linear Mode
