Ethereum and Ethereum Classic is a case study of a hard fork. The DAO plan builds a crowdfunding platform based on Ethereum smart contracts. It was officially released in May 2016 and ended in June of that year. Raised more than 160 million U.S. dollars.
Afterwards, The DAO was exploited by hackers to exploit loopholes in smart contracts. Transferred $50 million worth of Ethereum. In order to save the investor’s assets, The Ethereum community voted to alter the Ethereum code. hoping to recover funds.
For this reason, Ethereum hard forked at block 199000, The fork rolled back the Ethereum transactions (including the hacker’s). However, some people believe that this violated the decentralized and immutable feature of the blockchain, and insisted on mining on the original chain, thus forming two chains, A chain that does not recognize the transactions that were rolled back – ETC, And a chain that recognizes rolled back transactions – ETH, Each represents a different community consensus and values
A person holding an ether at the fork holds both ETH and ETC after the fork.