Distributed Ledger
A database that is consensually shared, replicated, and synchronized across multiple sites, institutions, or geographies. Unlike a centralized database controlled by one entity, a distributed ledger has no central administrator — each participant maintains an identical copy. A blockchain is one specific type of distributed ledger that organizes data into chained blocks.
“Bitcoin's distributed ledger is maintained by thousands of nodes worldwide, each holding an identical copy of every transaction since 2009, making censorship or tampering practically impossible.”
Blockchain
A distributed, append-only digital ledger that records transactions across a network of computers in a way that makes it cryptographically secured and practically impossible to alter historical records. Each block contains transaction data and is linked to the previous block through a cryptographic hash, forming an immutable chain.
Node
A computer that maintains a copy of the blockchain and participates in validating and relaying transactions. Full nodes store and verify the complete blockchain history independently. Light nodes store only block headers for efficiency. Archive nodes retain every historical state of the blockchain. The more nodes a network has, the more decentralized and resilient it becomes.
Decentralization
The distribution of control, authority, and data processing across a network of participants rather than concentrating it in a single entity. In blockchain, decentralization means no single party controls the network, making it censorship-resistant and reducing single points of failure.