What is a decentralized exchange

A decentralized exchange is a place to trade that does not take the customer's coins into a company account first. The trader keeps a wallet. The trade is a transaction on a chain, or a match against a pool of coins already sitting in a contract. There is no deposit button that moves the balance onto a private ledger. The chain is the record.

Two designs cover most of what people mean. An automated market maker is a pool. A trader swaps against the pool, and the price moves as the pool's mix of coins changes. Uniswap is the usual example. An order-book exchange keeps bids and offers, closer to a stock market, and settles the match on a chain. Hyperliquid's perpetuals are that second kind of idea applied to a futures book. Raydium, on Solana, runs pools, and the protocol has been buying its own RAY token back. The buyback note is here: https://cryptokeymedia.com/news/raydium-ray-buybacks

A centralized exchange is the other building. Coinbase, HTX, and WEEX take deposits. The customer has a login. The exchange can list a pair, pause it, or ask for a name. A decentralized exchange can still have a company that writes the software and a token that governs fees. Decentralized does not mean nobody is in charge of the code. It means the trade does not sit on that company's balance sheet.

The customer takes risks the login used to cover. A pool can be thin, so a large swap moves the price against the trader before the trade is done. A contract can be wrong, and a wrong contract can take the coins the wallet approved. An approval is a standing permission. A wallet that approved a bad contract has handed it a key to that token. Revoking the approval is the close. Leaving it open is how old permissions get used.

Perpetuals on a decentralized exchange are still perpetuals. The trader posts margin and bets a price, and the position can be liquidated. The difference is where the margin sits and who can halt the book. A centralized venue can change the leverage cap and say the trading page is the record, which is what HTX said about the Marriott contract. A decentralized book follows the contract that is already deployed, until someone with the right to upgrade it deploys a new one.

Fees go to the pool's liquidity providers, to the protocol, or to both. A liquidity provider deposits both coins in a pair and earns a share of the swaps. That deposit can lose value even when fees come in, if one coin runs and the pool is left holding more of the other. The fee is not a yield with a floor. It is a share of other people's trades.

A listing on a decentralized exchange is not a listing on Coinbase. Anyone who can create a pool can put a token in front of buyers. There is no auction hour and no company announcement required. That is why a new token can trade before any desk has written about it, and why the existence of a pool is not a check on the token. The pool is a price. It is not a review.

What comes next, for a reader, is which building a given trade is in. A login and a deposit means a company holds the coins. A wallet and a signature means the chain does. Raydium's pools and Hyperliquid's book are the second kind. Coinbase's spot book is the first. The word exchange does not say which one a person just used.