Print Queue Ports

Hi all,

I have a query regarding creating print queues on a server. When setting up
the print queue, there is the options of the different ports, eg lpt,
standard tcp /ip ports, lpr etc..
What are the differences / benefits of each one, and when would one be used
over the other. I'm just a bit confused as it seems to work regardless of
each one but would like to understand why and when they should be used.
If anyone could make this a bit clearer for me it would be much appreciated.

Thank You