You have with you DVDs from different parts of the world, including that British TV series DVD that you wanted to get for a long time. You are now back home and waiting for the opportunity to play that DVD. What could be a better time than this when you are off to a holiday with your car? You want your family to watch that DVD while you drive. When you try to play the DVD, you are surprised to see the words "wrong region" coming up on the screen. You do not understand what that is. Is your car DVD player not working? Or is it that the DVD is faulty? The packing in which the DVD came says that the DVD is region free, which would mean that the DVD is meant for Region 0, that it is region free. What could be the problem? You are not being able to figure this out.

A region 0 or a region free DVD plays on all DVD players, if the player is region free. But there remains the question of mismatching of the video formats. It is the question of compatibility between Phase Alternating Line (PAL) and National Television System Committee (NTSC). Your portable car DVD player, which you bought from the United States plays only NTSC standard DVD, while the DVD that you had bought from the United Kingdom has a PAL video standard. Even if the DVD is based on digital format, it matters less when the DVD has a PAL standard and you are trying to play it on your portable car DVD which is in NTSC. That DVD will not play in your portable card DVD player.

The so called regions, that we hear so much about when buying a DVD disc or a player, are catagorised in the following way:

1. Region 1 - The U.S., U.S. territories and Canada

2. Region 2 - Europe, Japan, the Middle East, Egypt, South Africa, Greenland

3. Region 3 - Taiwan, Korea, the Philippines, Indonesia, Hong Kong

4. Region 4 - Mexico, South America, Central America, Australia, New Zealand, Pacific Islands, Caribbean

5. Region 5 - Russia (okay, former Russia), Eastern Europe, India, most of Africa, North Korea, Mongolia

6. Region 6 – China

7. Region 0 – All the countries in the world.

There are mainly three basic television broadcast standards in the world and these are, Phase Alternating Line (PAL), National Television System Committee (NTSC) and Séquentiel couleur à mémoire, French for "sequential color with memory" (SECAM). These three standards are incompatible wit each other, which would mean that all both, the DVD and your portable car DVD player have to be of the same standard.

NTSC standard was developed in the United States and the first ever colour broadcast came to that country in 1953. This was obviously based on NTSC standard and is now being used by many other countries in the American Continent as well as Japan and the Philippines. It has 525 horizontal scan lines at 60Hz frequency, for which it is sometimes referred to as "NTSC-525". Out of the 525 lines, 486 lines are visible on the screen and the rest are synchronisation pulses, and for one, these are used to reposition the electronic gun in a television. Each of these visible lines is made up of 720 pixels, giving a total screen resolution of 720x486. NTSC has a frame rate of 29.97 frames per second which is rounded up and referred to as 30 frames per second.

PAL was developed in Europe and was introduced in early 1960's. PAL was available in most of the European countries by that time, except France, who developed their own SECAM system. PAL works on 625 lines per frame at 50Hz frequency. PAL uses a wider channel bandwidth than NTSC which provides a better picture quality. PAL has eight versions and these are PAL B, PAL G, PAL H, PAL D, PAL I, PAL K, PAL K, PAL N and PAL M. All of these have different specifications from each other. PAL is used in China, India, Indonesia, Israel, Laos, Nepal, Pakistan, Thailand, Lebanon, Iraq, Iran, and United Kingdom, some European countries, some countries in South America and also in Africa.

SECAM uses frequency modulation technology to encode chrominance information on the sub-carrier. Chrominance along with luminance is one of the two components of a television signal. It defines the two attributes of a colour. The hue of the composite picture is defined by the frequency, while the saturation defines the amount of black. Luminance is the mathematical component of the red, blue and green components in a colour television. This combination is used to produce other colours on the television screen. SECAM has the same bandwidth as PAL and operates on 625 lines per frame.

Region free portable car DVD players are capable of playing all region DVDs regardless of the region code of the discs. These DVD players have built-in code converters, which lets any region DVD to be played on such players and viewed on the screen. These portable car DVD players play any zone, area, region code DVD without any additional equipment. You can play any region, any code, PAL or NTSC DVDs from Europe, Asia or anywhere in the world. Region free portable car DVD players are those which do not have an internal region lock and hence they are universal players, and they can play DVDs from any region as shown above. These are specifically called Region 0 DVD players, which accept code locked DVDs from other regions.

One does wonder why the region wise coding is done in DVDs. Some say it is the only way by which one could project the right of issue of such DVDs. The other aspect, which is being conjectured, is to maintain the price of the DVDs at the regional level. For example, a DVD movie, which has been released in the United States, is priced quite high compare to the price as and when it is available in India. Therefore, with regional codes built in the DVDs, it will be difficult to play the same DVD in the United States, which has been coded for India.

In many legal views code enforcement is a violation under the WTO free trade agreement. The coding of the players violates this specific law. This coding of DVD players has been seen as a serious violation of Trade Practices Act, as per the law set down by the Australian Competition and Consumer Commission. A similar ruling also exists in New Zealand. As a result the DVD players, which include portable car DVD players, sold in Australia and New Zealand, are all of region 0 standard, meaning that the players are capable of playing any DVD, irrespective of their region coding.