Ethereum Classic is a decentralized blockchain platform that uses smart contracts to enable developers to build and deploy decentralized applications (dApps) on the network. Ethereum Classic was created as a result of a disagreement within the Ethereum community over how to handle a major security breach in 2016 which resulted in a hard fork.

The fork in the Ethereum blockchain that led to the creation of Ethereum Classic was caused by a security breach in a decentralized autonomous organization (DAO) called "The DAO." The DAO was a smart contract-based investment fund that allowed investors to vote on which decentralized applications to fund. It was created on the Ethereum blockchain and quickly became one of the most successful crowdfunding projects in history, raising over $150 million in ether (ETH).

However, in June 2016, a hacker was able to exploit a vulnerability in the smart contract code that allowed them to siphon off over 3.6 million ETH, which was worth over $50 million at the time. The Ethereum community was faced with a difficult decision about how to respond to this breach. Some members of the community believed that the best course of action was to implement a hard fork in the Ethereum blockchain, which would essentially create a new version of the blockchain with new rules that would prevent the stolen funds from being used.

Some members of the community believed that the best course of action was to implement a hard fork in the Ethereum blockchain that would essentially reverse the hack and return the stolen funds to investors. This would mean creating a new version of the Ethereum blockchain with new rules that would prevent the stolen funds from being used. This new version of the blockchain would become known as Ethereum.

However, other members of the community argued that this would violate the core principles of blockchain technology, which are decentralization and immutability. They believed that changing the rules of the blockchain in response to a hack would set a dangerous precedent and undermine the integrity of the network. They chose to continue using the original version of the Ethereum blockchain, which became known as Ethereum Classic..

Ethereum Classic maintains a similar codebase to Ethereum, but with some key differences. It still uses proof-of-work (PoW) consensus to validate transactions and secure the network, while Ethereum has transitioned to a proof-of-stake (PoS) consensus mechanism. Ethereum Classic also has a fixed supply of tokens, with a total of 210 million ETC tokens that will ever be created.

Ethereum Classic has a vibrant development community and ecosystem, with many dApps, tools, and services being built on the network. Some notable projects include the ETC Cooperative, an organization dedicated to supporting the development and growth of Ethereum Classic, and the Emerald Platform, a suite of tools for building and deploying dApps on the Ethereum Classic network.

Overall, Ethereum Classic represents a different approach to blockchain technology than Ethereum, emphasizing the importance of immutability and decentralization. While it has faced some challenges and controversies over the years, it has continued to attract a dedicated community of developers and users who believe in its vision for the future of blockchain technology.