A peer-to-peer order book-based cryptocurrency exchange is a type of cryptocurrency exchange that matches buyers and sellers directly without the need for intermediaries. In this type of exchange, buyers and sellers post their orders on an order book, which displays all the available orders and their corresponding prices. The exchange then matches the buyers and sellers based on their orders and executes the trades automatically.

One of the key advantages of a peer-to-peer order book-based exchange is that it offers a high level of transparency and control to the users. Since the exchange does not hold custody of the users' funds, there is no risk of hacking or theft. Additionally, users have full control over their orders and can modify or cancel them at any time.

However, there are also some risks associated with using a peer-to-peer order book-based exchange. The most significant risk is the potential for fraud or scams, as users are transacting directly with each other without any intermediary to verify their identity or protect against fraudulent behavior. As a result, users must exercise caution and conduct proper due diligence before engaging in trades on these types of exchanges.