Centralized exchanges (CEXs) — the large, familiar trading platforms most people start with — hold custody of user funds, match buy and sell orders on their own internal order books, and operate under their own company's infrastructure and terms of service.
Decentralized exchanges (DEXs) instead let users trade directly from their own wallets, using smart contracts to execute trades — often through an automated market maker (AMM) model, where trades happen against a liquidity pool rather than a matched counterparty order.
The core tradeoff is custody and trust: a CEX requires trusting the company to safeguard funds, honor withdrawals, and not misuse customer assets — a trust that has been broken dramatically in some well-known exchange collapses. A DEX removes that specific counterparty risk (your keys, your coins, right up until the trade executes), but shifts the risk profile to smart contract bugs, front-running/MEV, and the responsibility of managing your own private keys with no customer support to call if you make a mistake.
CEXs typically offer better liquidity for large trades, fiat on/off-ramps, and a simpler user experience; DEXs typically offer permissionless listing (anyone can create a trading pair), no account sign-up, and exposure to newer tokens before they reach centralized platforms.
Many active traders use both, choosing based on what a specific trade actually requires — deep fiat liquidity versus self-custody and permissionless access.
