Mac has the built-in DVD Player which you can use to watch DVD movies on your Mac. Sometimes however you may be required to change drive region on Mac when you play different region DVD on your computer.
It is because most DVD players, including the one in your computer, are locked to one or more region codes, and are able to play only discs with the same region code.
Instead of changing your drive region which is restricted to only a few times, you can download and use third-party DVD players to play DVDs with different region codes on Mac. For example, you can try VLC Media Player.
This is a free and open source cross-platform multimedia player. It can play most multimedia files, DVDs, Audio CDs, VCDs. To play DVD movies or DVD discs on Mac using VLC player, run the media player from Launchpad.
Hit File menu from the top menu bar. Choose Open Disc from the drop-down menu. You will open a new dialog like below.
The Disc tab will open automatically and you should find any inserted DVD disc. Click Open to play the DVD without changing your region code or drive region on Mac.