system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why are DVDs encoded differently around the world (i.e. Region 1, Region 2, etc.)?
gpt
They're not encoded differently, they're just locked to that region by the firmware on DVD players.  A Region 1 DVD player is technically capable of playing a Region 2 DVD, it's just got a little software switch saying "only play Region 1" set inside it.  It's possible to get region-free players or hack some models to ignore region codes.

Why do they do this?  Money.

The movie business has a long & complex history of studios giving exclusive distribution rights to distributors in different parts of the world.  The Japanese distributor has a contractual monopoly on movies from studio XYZ and doesn't want the Bolivian distributor trying to undercut their business, so the DVD standard included region codes.  This also allows companies to sell movies much cheaper in poor markets (eg - India) than they would in rich countries (eg - United Kingdom) without having to worry about movies from India getting moved to the UK and getting sold on the grey market.

This is the same reason that services like Netflix have different titles available in different countries.