dvd regions explained
Every DVD disc has region code (1 - 6) or has been manufactured region free. The idea behind region codes for DVD movies is quite simple. It is in place to control the exportation of movies to other countries, thus eliminating the possibility of purchasing a DVD movie which has yet to be played at the local cinema. This was great if you lived in the USA (region 1), but living in New Zealand (region 4), DVD releases were few-and-far-between, so purchasing a zone 4 player was a waste of money. But now it seems to be getting better with more releases being available.
Some clever people decided this was a bit harsh, so they decided to modify their own players to be either selectable zones or zone free (zone 0). The DVD manufacturers clicked onto the idea of zone free DVD players, deciding to make the discs only play in players that the zone is selected. Zone 0 will not play the majority of new releases any more.
Also, with the RCE (Region Coding Enhancement) discs now widely available in the market (The Patriot as example), these will not play in some previously auto switching modified DVD players, but still will work if you manually switch region codes i.e via the remote control.
If you look above, you can discover where the invisible region boundaries are. This may help you in purchasing a genuine DVD player for the region of your choice.