It seems that DeF is shifting traditional financial products to the open-source and decentralized world. I guess it could bring several benefits in comparison with traditional financial services. For example, lots of dApps developed on top of the Ethereum or EOS blockchains, are able to provide reduced operational costs and lower entry barriers. Also, feel free to check the repository of knowledge about DeFi https://defiwiki.org. You can find some helpful info re DeFi there.