Peer-to-peer technology behind Bitcoin. Blockchain is a Block network that stores transaction data that has been encrypted in a distributed network. This technology allows users to store digital data safely and authentically without being able to be changed by others. Blockchain initially appeared together with Bitcoin, but recently found many uses of this technology outside of the digital assets themselves. Blockchain began to be used by world-class companies such as Microsoft, Citibank, Visa and Walt Disney.