Like the Swiss Army Knife of crypto, Decentralised Finance (DeFi) apps strip away the middlehuman from financial transactions, using a combination of smart contracts and code to do all sorts of crazy stuff over the blockchain. DeFi tokens are linked to DeFi protocols, which in some cases are governed by their user base.
Now, DeFi is a pretty broad term (lots of tokens dabble in DeFi), so this list is compiled of tokens developed primarily as an asset to be used within an associated DeFi-based blockchain. We've also narrowed it down to tokens with established market capitalizations of $500m, including those oscillating around that watermark - 'cos we all know how quickly prices can change in crypto. It's worth noting the list does not include tokens belonging to blockchains that just support DeFi apps, nor does it include DeFi stablecoins.
As always, research as fully as you can before yolo-ing into anything.