NOTE: Before trying to add any network printers, be sure to know what the printer's hostname or IP address. Most printers have a label on them with a hostname; sometimes there's an IP address; sometimes both. If you know what the printer is called, you'll avoid printing on someone else's printer who has the same printer elsewhere.

NOTE: The instructions below are an example. Please do not use the numbers/names in the screenshots. 

To install a printer on a Mac, do the following: 

Click on the Apple Menu and open System Preferences

Click on Printers & Scanners

Click on the '+' icon underneath the Printers list

If you have the name of the printer, select the printer name from the list, then click A

If you have an IP address for the printer, click on IP and enter the IP address in the given field

Let the setup run

The newly added  printer should appear under the Printers list now. It should be listed as either the name or the IP address, depending on which way you added above

Now you'll be able to select the printer when you need to print something out.