DeFi, or decentralized finance, is inextricably linked to the rise of cryptocurrencies and blockchain technology. It is both a large-scale vision for a new way of conducting financial transactions and an umbrella term for various decentralized financial products and services known as protocols. While DeFi owes its existence to the launch of the Ethereum blockchain and smart contracts in 2015, it saw its major period of growth, known as DeFi Summer, in 2020.