Glossary
Blockchain
An append-only ledger replicated across many nodes, where blocks of transactions are linked by cryptographic hashes and ordered by a consensus rule.
A blockchain is a distributed database with three defining properties: it is append-only, every entry is cryptographically linked to its predecessor, and the ordering is decided by a public consensus rule rather than by a central operator.
The combination makes the history extremely expensive to rewrite once buried under enough new blocks, which is what lets strangers settle value transfers without trusting each other or a middleman.