Here's a breakdown:
* Differences from the TCG: While the core rules are the same, there are some differences in the card pool, rulings, and even some card effects.
* Exclusives: There are cards exclusive to the OCG that are not available in the TCG, and vice versa.
* Limited List: The OCG has a different Limited List, which governs the number of copies of certain cards that can be used in a deck.
* Translations: OCG cards are printed in Japanese, and while some translations exist, they may not be officially sanctioned.
Essentially, the OCG is a separate version of the Yu-Gi-Oh! Trading Card Game, mainly played in Japan with its own set of rules and card variations.
If you're interested in learning more about the OCG, you can find information online on websites dedicated to the game, as well as forums and communities.