Order book exchanges are capital efficient because price is maintained locally, where the bids meet the asks. The price is not a global state (like in an AMM), but an emergent dynamic property of the order book, allowing for an arbitrary liquidity curve as opposed to a deterministic one. Moreover, rich pricing and volume information is made visible to traders, making informed trading decisions easier by understanding market demand and supply. On an AMM only market orders are possible (trades at the current price), whereas order book exchanges work with limit orders. Limit order is an order to buy or sell at a specified price, which remains in effect until executed or canceled by the user. In practice, it allows for more sophisticated trading strategies commonly used in traditional finance and also allows the trader to name their price.