DeFi, or decentralized finance, refers to a new wave of financial applications and platforms that are built on blockchain technology and operate without the need for traditional intermediaries such as banks or financial institutions. These platforms aim to provide users with greater control over their finances, as well as increased transparency and security.

Some of the most popular DeFi platforms include:

1. Uniswap: Uniswap is a decentralized exchange platform that allows users to trade various cryptocurrencies directly from their wallets without the need for a central authority.

2. Compound: Compound is a lending platform that allows users to lend and borrow cryptocurrencies using smart contracts. Users can earn interest on their deposits or borrow funds at competitive rates.

3. MakerDAO: MakerDAO is a decentralized lending platform that allows users to create and manage stablecoins, which are cryptocurrencies pegged to the value of a fiat currency such as the US dollar.

4. Aave: Aave is a decentralized lending platform that allows users to lend and borrow cryptocurrencies using a wide range of collateral assets. Users can earn interest on their deposits or borrow funds at variable interest rates.

5. Yearn.finance: Yearn.finance is a decentralized platform that allows users to optimize their yield farming strategies by automatically moving their funds between different DeFi protocols to maximize returns.

6. Synthetix: Synthetix is a decentralized platform that allows users to create and trade synthetic assets that track the value of real-world assets such as commodities, stocks, and currencies.

7. SushiSwap: SushiSwap is a decentralized exchange platform that is based on the popular automated market maker (AMM) model. Users can provide liquidity to the platform and earn rewards in the form of SUSHI tokens.

These are just a few examples of the many DeFi platforms that are currently available in the market. As the DeFi space continues to evolve, new platforms and applications are constantly being developed to provide users with even more opportunities to participate in the decentralized finance ecosystem.