Decentralized Exchange: This variety of exchanges stay true to Nakamotos ideology for cryptocurrencies. Hence, decentralized exchanges focus on protecting the anonymity of users and improving the security of the platform.
No. Mr.Satoshi's ideology must be NOT depending on any services but with your friends and colleagues. It means decentralized way of exchange will not fulfill what Satoshi was dreaming but exchanging within ourselves in P2P way must be a true way of following as per Satoshi's ideology.
Moreover, even in decentralized environment at the time of "actual exchange" we need to move up all of funds to the centralized authority and need to depend on them to complete the transaction. Even here, exchange operation is happening very similar to escrow, I am not ready to accept is works in complete decentralized manner. Probably all decentralized exchanges are the true hybrid exchange as it ensures only half of decentralization.
The OP is just promoting his services
This is the reason his explanation on various types of exchange are not enlightening us into anything new. I believe this is not a right way of having discussion here and probably it is an example of misusing "freedom of speech" which is a big moto of this forum.