A continuously accumulating decentralised data entity in which all transactions are chronological, validated by all parties and stored in a way that cannot be altered or falsified.

A blockchain generates a digital log of transactions. The log records are copied and stored in a decentralised way in public digital networks without a dominant server. Ethereum (2014) is the largest and best known blockchain. A blockchain can be used to create a variety of web 3.0 applications, services and products. It is practically impossible to alter or tamper with the transactions recorded in the blockchain afterwards, because each block in the blockchain contains the hashtag of the preceding block.