Depends on the Mac.
The OLD ones used a proprietary monitor type, but those haven't been around in ages.
Everything in the last half-dozen years has a standard PC-type videocard with a standard VGA out or at least a DVI>to>VGA adapter (which you can also purchase separately).
But you weren't specific as to model and that's like trying to guess from "What engine does my car have in it?" with no other info...('ya gotta be specific when asking a question here)
