What Are the Main DeFi Protocols and What Does Each One Do?

DeFi can look like a list of unrelated names. Aave lends, Uniswap swaps tokens, Curve focuses on specific markets, and MakerDAO built infrastructure around a decentralised stablecoin.
For someone new to decentralised finance, it is not obvious what connects these projects — or why there are so many of them.The useful way to approach the main DeFi protocols is not as a ranking. It is as a map of financial functions.Traditional finance separates lending, trading, market making and money crea