NetWare's print monitor (Nwmon.dll) sends print jobs to Pserver print devices. Pserver is a print-device standard developed by Novell.
In most situations, the print server drives the trnsport process of delivering the print job over the port. In the case of a Pserver print device, Nwmon.dll manages the communication between the device and the server. The Pserver "grabs" the print job from a passive print queue.