Does a printer require a Network Card?

Some printers support network in order to share its resources. Usually such printers have a network card installed when it was assembled. If you printer have a network card you will be able to find RG-45 port. But the best way is to check the manual or manufacture website.

If you share your printer through your computer which is connected to network then you don't a network card because the printer uses that one which is inside of your PC.