One of Yearn's most popular products are the yVaults.
The goal of the yVaults program is to empower the community to quickly and safely create and utilize the most effective yield farming robots created by the industry's best strategists.
Currently there are 2 versions of the yVaults available in our yearn.finance website. You can see from the list which vaults are V1 and which are V2.
For the end user the main difference is the fees charged, find here the explanation. Once you understand it, pick the yVault that matches your tokens and APY desired.