Blockchain, or distributed ledger technology, is a database that is consensually shared, replicated, and synchronized.
The replication and storage of transactional data by each party, or node, on a blockchain network is known as a distributed ledger. Conflicts, or inaccuracies within the database, are automatically resolved with predefined ledger rules.
Blockchains, while similar to databases, are not used for general data storage, but rather hold information about transactions. Sometimes the blockchain will contain the transactions themselves or may include the proof a transaction is valid.