A:Answer It depends - your computer has to have a VGA output (it looks blue, it's probably being used for the monitor you are currently using, or maybe you have a second output), a DVI output (looks longer than the VGA and white), or an HDMI output (this one has the best quality, but you'll have to get the cable separately).
In this image (http://www.what-is-my-computer.com/images/hdmi-vga-dvi.jpg), from left to right, those are HDMI, VGA and DVI outputs. Bear in mind you can also buy a graphics card that has one of these outputs if your computer doesn't have any one to spare.