A lot of people know that the concept of blockchain is derived from Bitcoin. However, Bitcoin is not the same as blockchain. Blockchain is the technical foundation of Bitcoin. 

Essentially, blockchain technology is the combination of distributed data storage, peer-to-peer transmission (P2P), encryption algorithms, consensus mechanism (a mechanism that maintains the operation and fairness of the blockchain system and provides incentives to the blockchain maintainers), etc. It is a distributed and decentralized digital database. All node maintainers jointly manage, transmit and synchronize data, store data in blocks and chain structure, and use cryptography to guarantee the security of transmission and access, which can realize a technical system where data is stored consistently and cannot be manipulated or changed. Different from a typical centralized database, blockchain is a shared database where all node maintainers can synchronize the data. Therefore, it is difficult to tamper with the data arbitrarily.

To put it simply, blockchain is a shared, immutable ledger. Blockchains store data in blocks that are linked together in chronological order. Each block contains the encrypted hash, timestamp, and transaction data of the previous block.