Blockchain Blockchain, by definition, is a distributed database keeping data records about developments in a digital world. This system is distributed and available to most of the users. Data records can be input only with consent of the majority of the users. Moreover, once recorded the data can’t be changed or erased. Imagine that in a busy street you see a tree that has just grown from beneath asphalt within a second. The same second everyone witnessing this, were connected to a computerized polygraph and asked to describe what exactly they had seen. As a result they, word for word, gave a clear account of what had happened. Are there any doubts that the tree has grown through the asphalt? This is the basic principle of blockchain – a powerful invention, misunderstood by many despite its ability to drastically change our interaction with the digital world.