a) Network printer / printer server box
For most printers that have a built-in network interface or that are to the network using a printer server box the "LPD" or "Socket / Jetdirect" network protocol can be chosen. Most network printers and printer servers support several protocols, often also the IPP protocol is supported. If you don't have information on the network protocols supported by your printer or server, you can try all three protocols.
b) Printer attached to other computer in network
If the printer is connected to another computer in the network, choose either "Windows network printer" or "Linux network printer" depending on the computer. Current Apple computers also support the IPP protocol.
Of course the printer must be "shared" so that it accepts print jobs from other users in the network.
Note: Printers that have been shared for network use from Linux and Apple servers are automatically visible on other Linux clients, provided that "printer browsing" is enabled on the server & client. If you print to such a shared network printer the print job is processed on the server – this means that TurboPrint's printer status monitor cannot show a print preview or control print jobs on the server.
It often makes sense to set up a print queue also on the client computer - print jobs are processed locally and print preview is possible. In this case the server will pass through all print data directly to the printer port.
c) other printer port on local computer
If your printer is not connected via network but to a local port that is not listed under "Standard printer", choose "Other (CUPS URI)".