The difference is the type of printer that will be available. Classroom labs do NOT have multifunction printers so you will not be able to see a list of you print jobs. You will need to swipe your card and all print jobs will be released. Multifunction printers, found in the library, will have a display allowing you to see your list of jobs and print only the ones you wish.
Each printer in open labs and classroom labs will be labeled appropriately with printing instructions.