Bitcoin is a kind of virtual digital currency proposed by Satoshi Nakamoto in 2009. Its characteristic is that there is no centralized issuer, and the total amount is fixed, which is 2 1 10,000 sheets. Moreover, it is not a one-off problem, and it needs to be mined by miners. Because it is a decentralized structure, trust needs to be realized by cryptography and * * * knowledge mechanism technology.

Blockchain is a general technology derived from Bitcoin, which realizes a decentralized database model. Bitcoin can be defined as blockchain 1.0 because it has no concept of smart contract. The key technologies of blockchain include cryptography encryption and decryption and * * * knowledge mechanism. Blockchain is generally used to combine with specific business logic, which needs to rely on smart contracts, which provide an execution mode without human intervention.

The initial currency issuance of ICO originated from the concept of initial public offering (IPO) in the stock market, and it was the first time that the blockchain project issued tokens to raise bitcoin and solve common digital currency behaviors such as Ethereum.