Blockchain
A blockchain is a shared digital ledger that records transactions in linked batches and is maintained by a network of computers.
A blockchain is a type of database used to record information, most commonly cryptocurrency transactions, across a distributed network of computers. Transactions are grouped into “blocks,” and each block is connected to the one before it using cryptographic proofs, creating a chain of records. Because many participants keep and check copies of the ledger, changing past records is extremely difficult without the network rejecting the change.
Blockchains matter because they allow people and applications to agree on who owns what or what happened without relying on a single central administrator. In crypto, a blockchain can track coin transfers, run smart contracts, or record ownership of digital assets. A practical comparison is a shared spreadsheet that many people can view and verify, but where new entries must follow agreed rules and past entries are designed to be tamper-resistant.
Other terms in Blockchain Fundamentals
Atomic Swap
A peer-to-peer crypto trade that lets two parties exchange different coins directly without relying on a centralized exchange or custodian.
Block (Blockchain)
A block is a bundled set of blockchain transactions and metadata that is added to the chain after the network accepts it as valid.
Blockchain Fork
A blockchain fork is a split or change in a blockchain’s rules that can create two different versions of the network’s transaction history.
Consensus Mechanism
A method a blockchain network uses to agree on valid transactions and the current state of the ledger without a central authority.