Sure, a centralised exchange means that a 3rd party manages the entire system, so when you send coins to an exchange like huobi the coins are in their possession and can be subject to hacks, the site going down or legal issues. A decentralised exchange means you remain in ownership of your coins and instead of using a business you trade via smart contract instead where trades are finalised on a chain and not by the servers of the exchange where you have no chain confirmation of the trade