The difference between CEX (Centralized Exchange) and DEX (Decentralized Exchange) and which one is better depends on your needs and trading experience. CEX is a type of exchange where trading is done by an intermediary institution. It is usually more user-friendly and allows trading in fiat currencies. Its advantages include ease of use, as well as the opportunity to trade on a larger platform. However, CEX collects users' personal information, which can lead to various security risks, such as the possibility of hacking.

On the other hand, DEX is a peer-to-peer system where users trade directly with each other without the participation of a central authority. Its biggest advantage is that you have complete control over your assets and it is relatively good from a security perspective.

So, if you want a simple, reliable and fiat currency trading, CEX may be the right choice for you. If privacy and security are more important to you and you want to maintain control, DEX may be the right choice for you.