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.
“Bitcoin is considered highly decentralized because thousands of nodes worldwide independently validate transactions, and no company or government can shut it down.”
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.
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.
Consensus Mechanism
The method by which a decentralized blockchain network reaches agreement on the current state of the ledger and which transactions are valid. Consensus mechanisms solve the problem of coordinating untrusting parties without a central authority. Major types include Proof of Work, Proof of Stake, Delegated Proof of Stake, and Proof of Authority.