The Ethereum Classic cryptocurrencie is based on the original blockchain Ethereum. In June 2016, The DAO, the first smart-contract, knows a flight million. To remedy this, a hard fork was held on 20 July 2016. A hard fork is a change in the blockchain, causing the separation of blockchain in 2: the modified channel and the original channel. They say a chain is winning when the majority of the community following one of the two chains. Today, the winning chain is the modified chain (Ethereum) and the original chain continues to exist under the name of Ethereum Classic. Consequently, all ETH on an address before the hard fork are also present on the ETC channel (same address).