I'm new to Macs - just bought a MacBook Air. I have a lot of DVDs that are on disc and also one (so far) transferred to an external hard drive that can be read both by my old PC and by my MacBook Air. The PC can play the movie from the external drive, but I can't figure out how to play it on the Mac. I travel a lot and don't want to have to travel with DVDs and buy an external DVD reader to travel with - I'd rather be able to do it all from the external hard drive, which I'll have to travel with anyway. How do I play movies on a Mac? I tried pulling them into the iTunes library, but that doesn't work. I don't know anything about file types for movies. The original DVD and the copy on my external drive each has twenty files, with extensions ".bup," ".ifo," and ".vob." I have no idea what these are, which is the movie itself, etc. Any advice would be greatly appreciated!