Not entirely dissimilar from a database, Blockchain is a system for recording data. Blockchain claims immutability, resistance to hacking, and capable of providing an indelible record, typically of transactions. This is achieved by creating a copy of the Blockchain (a block) on every computer on a distributed network, securely linked with cryptography. Blockchain is most encountered in the context of cryptocurrency but has other real or proposed applications. These include providing traceability of goods, chain of custody, and various record-keeping applications such as healthcare, insurance, and real estate.