The Mac Book, Mac Book Pro, & Mac Book Air each have a Mini Display Port that means that you can connect an external display or projector using an adapter. You can use an external display as your main workspace or to extend your desktop, or you can work in mirrored mode with a projector so you can view what your audience sees. Use the Mini Display Port to DVI adapter to connect an advanced digital monitor, such as the 20- or 23-inch Apple Cinema Display.