The Hollywood movie studios are the main culprits here.

Historically, they've released movies at different times in different places in the world.

So they don't want a film that's only been released in the USA to be viewable in Europe until they say so.

Sometimes there may even be restrictions on which countries a film can be shown in - for years, the film "Clockwork Orange" wasn't available in the UK as the director, Stanley Kubrick, had requested that it was withdrawn in that country.

Trouble is, in this ever shrinking world, we want to be able to watch what we want, when we want. Regardless of whether a faceless film studio thinks we "should".

Which is where DVD unlock codes come in handy.

Most DVD players are made in a factory that doesn't initially know where the player will finally be sent. So it's easiest for the manufacturer to make one machine and then use a few software codes to lock it to the destination country and keep the major copyright holders happy.

This means that when you buy your shiny new DVD player, it will likely be locked to only play discs from your part of the world.

The good news about this globalization is that you can type in a few codes on your DVD remote and release your player to play movies from anywhere. Whether they've been released in your country or not. So that art movie from France now becomes available to you. As does the DVD you bought to remind you of your holiday and any other disc you care to watch.

Check whether your DVD player can be made multi region here.

Some people are worried about invalidating their warranty if they unlock their DVD player.

This isn't a problem as it's just a matter of pressing a sequence of codes on your remote control handset. You're not taking the lid off your machine or doing anything that could invalidate its warranty.

The other common worry is whether or not it's legal to unlock a DVD player to be able to watch movies from other parts of the world.

So long as you're watching a DVD that was bought legally and isn't a pirate copy, there should be no problem.

Unlocking your DVD player isn't illegal. And doing this won't get round any other copy protection built into the DVD, so you're not breaking any rules there either.

It really is a very simple matter and the people I recommend will help you if you're struggling (this isn't likely but it's nice to know the option is there).