Decentralized finance (DeFi) refers to financial smart contracts, decentralized applications (DApp), and financial protocols built on the blockchain. DeFi can be found in many scenarios, including decentralized exchanges, digital assets, payments, lending, and so on.
Decentralized Applications (DApps) are also known as distributed applications. In the crypto world, it refers specifically to Apps running on blockchain networks such as Ethereum, OKC, Polygon, and others.