A blockchain is a secure, decentralized data record. It can store many information types, including transaction, ownership or location histories. Blockchain is often referred to as a distributed ledger with each unit, or block, in the blockchain containing the previous block, a timestamp and the data it’s recording.
Blockchains use cryptographic hash functions — a mathematical algorithm that’s nearly impossible to reverse — to validate data movement in the chain. This process makes the blockchain highly secure and transparent, as each blockchain change is visible and unchangeable.
Blockchain rose to popularity in 2008 when it was used to create Bitcoin. Blockchain is often used with cryptocurrencies to record transactions — its decentralized nature made cryptocurrencies the first digital currency to eliminate the risk of double spending without the need of an administrating authority.
Still, blockchains and cryptocurrencies do require some governance and support, similar to open-source projects. Developers will often volunteer their time to make updates and correct errors.
Outside of cryptocurrencies, blockchain has many business applications that increase automation and efficiency. Using blockchain, an organization can securely send data, record transactions or track products without the need of intermediaries. In the U.S., state governments are exploring blockchain for voting and filing important paperwork.