Currently, the traditional financial sector has entered a completely new era with the opportunities offered by blockchain technology and smart contracts, led by cryptocurrencies such as Bitcoin and Ethereum. In this new era, one of the most important innovations brought to the finance sector by blockchain technology, which has a distributed structure and offers a secure, transparent, and unchangeable record system, is the decentralized finance application called DeFi. DeFi has started to be accepted as an ecosystem that transforms the traditional financial system, enables a system that works to replace central authorities, and leverages blockchain technology to create a more open and accessible financial system of its essence. With DeFi applications, it is aimed to carry out transparent and secure transactions without the need for banks or various financial intermediaries. Thanks to decentralization, users are given full control over their assets, and their dependence on central authorities is reduced. However, although the DeFi ecosystem has advantages such as decentralization and transactions without an intermediary institution, there are various systematic and non-systematic risks (for example, regulation, consumer, technology, and operational) within the ecosystem. These risks expose users to loss of investment. By understanding the basic technology in the system and taking strong security measures, users can reduce these potential risks. DeFi users should be aware of these potential risks and exercise caution when joining new platforms or investing in decentralized applications. In conclusion, with the recognition of the innovative features brought by decentralized finance and the reduction of potential risks within the system, faster, cheaper, and more accessible financial services are likely to be delivered, and the DeFi ecosystem is likely to become more mainstream in the future.