Today when we hear the word “blockchain” we think about Bitcoin, Ethereum and other cryptocurrencies. The distributed ledger technology as it exists now first appeared in 2009 together with the first cryptocurrency. Bitcoin, as well as the vast majority of digital currencies are based on blockchain. Probably the only exception is the project and the coin called IOTA that is based on Tangle technology and does not include blockchain. Anyway, it soon became clear that cryptocurrencies are just one possible way to apply the distributed ledger technology. Blockchain is actually a new and advanced way to store and exchange information, and if we stick to such a broad definition it will become clear how big is the potential of these technology.