Intent-driven applications will be an important component of Decentralized Finance (DeFi) 3.0. This article introduces the potential of intent-driven applications and emphasizes the need to be concise when exploring all possible use cases. It then delves into several popular current decentralized trading models: the Central Limit Order Book (CLOB) model, the Liquidity Provider (LP) model, the Automated Market Maker (AMM) and virtual Automated Market Maker (vAMM) models, and hybrid models. Each model has its own advantages and disadvantages. The article also discusses the aggregator model and the solver model (intent-driven), noting that the solver model's application in the derivatives field is still immature but has made significant progress in other cryptocurrency areas. Finally, the article summarizes three main challenges in the intent-driven field: solver competition leading to centralization, fragile solver infrastructure for complex intents, and high thresholds for deploying and operating solvers.