You can connect a MacBook computer to an external monitor with a VGA or DVI port to increase your screen real estate. MacBook computers are capable of two display settings when connected to an external monitor. Screen mirroring, which is the default setting when you connect a MacBook to a monitor, shows an identical image on both screens. This is a good option if you want to use the external monitor as the primary display. You can also arrange the MacBook screen and the external monitor to act as an extended desktop and use both at the same time.
Connect the Mini DisplayPort cable to the MiniDisplayPort to DVI or VGA adapter. To determine which type of adapter you need, consult the owner’s manual for the monitor or look on the back to see which type of port it uses.
Plug the Mini DisplayPort cable into the Mini DisplayPort port on the left side of the MacBook.
Plug the DVI or VGA adapter into the port on the monitor. Turn on the monitor. The “Display” system preference window will open automatically so you can adjust the settings.