More Mac 101, tips and tricks for new Mac users.
Ever wonder how your documents go from screen pixels to paper printouts? CUPS is the open source printing system that powers Mac OS X output, built for a variety of UNIX systems and now developed (or at least assimilated) by Apple. It provides print services by creating a representation of the page contents, and converting that data into formats that any number of printers understand.
OS X applications don't need to know the printer specifics. All they have to provide is a page description, which they pass along to the CUPS server. The server takes over from there and sends the document data to the active printer.
You can access your CUPS-based printers via a Web administration page, if the mood strikes you. It's easy; point your Web browser to http://127.0.0.1:631/printers. From there, you'll be able to check print queues, show completed print jobs, and more. You'll also be able to print a test page, pause the print queue, cancel all jobs, and set the default printer -- among other maintenance and administrative tasks. Most of the things you'd do there are also manageable via System Preferences, but it's nice to know what's underneath.