Decentralized exchanges can replace the current centralized exchanges which have so many drawbacks that are not the part of modern decentralized exchanges. Recent act of hacking on the Binance exchange must have forced them to think about the alternative of the centralized exchange.
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After deep study of concept of decentralized exchanges Binance has decided to launch its own Binance chain that will focus on transfer and trading of blockchain assets. The concept of decentralized exchange is simple the buyer and the seller doesn't need to hand over there coins to the third party.
The concept of decentralized exchanges involve smart contract and it only allows you to trade assets on common block chain that's why this concept is not so popular however in future when cross blockchain trading will become practical then more investors will prefer decentralized exchange over centralized one. Binance Centralized and Decentralize exchanges will have interdependence however there are no details about the working model of the concept.