What is yVaults?

yVaults are a feature of the Yearn.Finance protocol which automate the process of yield farming. Users deposit tokens into a yVault, then Yearn borrows stablecoins against the user's asset. The stablecoins are then used for yield farming in various protocols, with the vault shifting strategies as opportunities change. As gains are realized on stablecoins, Yearn converts the gains back into the user's original asset and the user's rewards are paid in that asset. Each yVault has a different annual percentage yield (APY).