People use the term ‘blockchain’ to mean different things. The terminology can be confusing. Sometimes they are talking about a digital cryptocurrency like Bitcoin or Ethereum. They also might mean to refer to a blockchain that functions as a smart contract. Most of the time, however, they are talking about a type of distributed ledger that contains a list of transactions and is shared among a number of computers, rather than being stored on a central server.
Blockchain technology first gained real traction through the introduction and popularization of digital currencies, also known as cryptocurrencies, in 2009. Since then, adoption of blockchain, especially surrounding cryptocurrencies, has skyrocketed. However, the applications of blockchain technology are not limited to just digital currencies. The technology can be generalized to be the backbone for transactional platforms across multiple domains.
Across all of the various blockchain use cases, there are certain themes that emerge. The data within the individual blocks of a blockchain contain transactions, usually financial transactions. One of the central tenets of a blockchain is that there is usually no central authority. Instead, transactions are replicated across a number of participating systems in near-real time. The blockchain uses cryptography and digital signatures to prove identity, authenticity, and enforce access rights. Additionally, a blockchain contains mechanisms which make it difficult, if not impossible, to change the data behind the recorded transactions. Together, all of these features make the blockchain a very attractive technology for the future.