Binance has one of the top three performing exchange involved in crypto trading and mostly all other features an exchange can offer. Binance Dex is an decentralized version of Binance. Usually a Centralized Exchange is owned and run by authrorities and founders but a dex platform is more transparent version where you trade with peers without any central or third parties involved.
Best thing about binance dex platform is that almost all top quality coins are listed to trade and easy to use web platform and you dont need to connect your wallet as it optional because Binance Dex offer multiple wallet connect options. You can import earlier wallets with keystore or private keys or you can create new wallet and start using the Binance Dex platform by sending any crypto that is available on Dex to trade or you can simply send Eth and btc to start using all the available coins on Dex.
Binance Dex was introduced way earlier than any currently available Dex platform and it make the trading as easy you dont need to send coins to exchange and bear transaction fees. Binance Dex is still quite frequently used and preferred decentralized exchange where only you have control over assets and trade multiple variables with low fees