What is a Region 1 DVD?

I have just purchased a HD dvd player. It will play any region HD-DVDs as they are not region coded, but only region 1 regular DVDs.

What is a region 1 dvd vs any other type of dvd?
There are different region codings depending on the location of where you live. NTSC Region 1 is for the US and Canada, Pal is for Europe, etc. There are 6 region codes world-wide. An NTSC region code 0 can also be played anywhere in an NTSC region. South America is NTSC, but not region 1, therefore NTSC 0 code can be played in the US and South America.
Check out Amazon.com, and they have a great explanation on region coding around the world.
DVDs are coded by region. For instance, I wanted to see what all of the fuss was about with Kubrick's last movie featuring Cruise. A scene was censored only in the United States so I went out and bought a Zew Zealand release but I had to get a region-free DVD player to watch it. (Something to do with the hand-jive....)

Thw studios want to stagger the release of movies world-wide so The United States is region one and there are numbers for each part of the world. this will maximize profit as DVDs could be released in the USA while the movie premieres in Australia. A DVD player is set to work movies from that region, but not others.

My Apple computer will play DVDs from all regions until I have played four of them and then it sets itself to that (last played) region.

There is a web site, I don't remember it's address where you can download instructions to re-set your DVD player to another region or to '0' which is region-free.
Thanks guys.....your answers were a big help.

I don't buy, I only rent......so, I should be pretty safe with anything I get from NetFlix.