Virtual Printer is a piece of software which allows to send printing tasks (e.g. for invoices and shipping labels) directly to a printer without the need for a preview to be displayed in the browser which is standard behaviour for printing from a browser.

Using a virtual printer will also improve efficiency, as you will be able to assign specific printers to different printing templates (invoice/pick list/ etc). As an example, this will allow a user to select multiple orders requiring different printers and print them at the same time.