Centralized vs Decentralized Systems
A centralized system is run by one authority; a decentralized one is run collectively by many independent participants.
In depth
Your bank is centralized: one company keeps the ledger, decides the rules and can freeze or reverse transactions. A decentralized network like Bitcoin spreads the ledger across thousands of computers that must agree with each other, so no single party can change history or block a payment. Think of a shared group notebook where every member has an identical copy versus one notebook locked in a manager’s drawer.
Why it matters
Almost every trade-off in crypto — speed vs censorship-resistance, convenience vs control — comes back to this distinction.