The system on which all Bitcoin transactions are stored, which is open to all users. It’s formed of a series of subsequent blocks (connected by a chain), each of which is strictly limited to a certain number of transactions. This type of system is protected from interference or manipulation by the fact that each subsequent block in the chain contains the hash of the previous block. Working on the blockchain is made possible by the activities of miners. The data storage system allows you to know how many bitcoins belong to each address at any moment in the system’s existence.