A print server is a device that can 1)store ("spool") and 2)manage the printing order of print jobs issued by PCs on the network. Print servers can be implemented in both hardware and software. The former type requires a print server device be directly attached to an interface on the printer (serial/parallel/USB), while a software-based print server utilizes a specific program installed on a computer. Low-priced compact hardware print servers are now available. In a Windows-only environment, printer sharing is possible via the "File and Print Sharing" feature of Windows. However, this method requires the PC connected to the printer be always running for other clients to print. If you feel this scheme is rather inefficient, it is recommended to implement a (hardware) print server instead. Printer sharing among Macintosh clients via AppleTalk protocol is possible. Note that only PostScript printers can be used in mixed Windows-Macintosh environments due to the way Macintosh OS is designed.