What is a hard fork in Crypto?

Related questions

1. Are ether and ethereum the same?
2. Where can you buy ethereum Classic?
3. What is a Bitcoin hard fork?
4. What is happening with ethereum Classic?
5. Is ethereum a currency?
6. What is ethereum classic Cryptocurrency?
7. What is a Chinese Dao?
8. Is there a max supply of ethereum?
9. Which country currency is ether?
10. What happens hard fork?

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