Out of the box, a Mac should be able to play most mainstream video files. Any file not supported should easily be remedied by the many video codecs available on the internet. If you encounter a video file that cannot be played, do a quick search on the internet for the file extension's codec.
The types of video files that can be played on a mac is any kind of video file if using an adapter called MacApper. This is used to decode the video files so you can play them on your Mac. This adapter is a free application for your mac abeling you to play these files.