Decentralisation

Decentralisation describes how widely control over a network is spread. A highly decentralised blockchain has many independent node operators, miners or validators in different countries, open-source software that anyone can inspect, and no single company able to change the rules, freeze funds or censor transactions.

Decentralisation is the main reason public blockchains are interesting at all: it is what makes the ledger hard to tamper with and the money hard to confiscate. But it is a spectrum, not a yes-or-no label. Useful questions include: how many entities produce most blocks, who holds most of the tokens, who can upgrade the smart contracts, and whether the project depends on one company's servers or front-end.

Many projects call themselves decentralised while key functions remain controlled by a small team, a multisig of insiders or a foundation. Greater decentralisation usually costs speed or convenience, a trade-off often described as the blockchain trilemma.