wRING or Wrapped RING is a token that is a representation of the value of RING based on the index when you wrap and unwrap respectively. Simplifying, it is a token whose amount doesn't increase but so it does its value.

There is a Medium post with a deeper explanation of how you can benefit from wRING and what purposes it serves.

https://medium.com/@ringfi/wring-wrapped-composable-token-by-ringfi-1d1329b80226