It's where you can see all your challenges - sent and received up to past 3 months - with results of challenge points (CPs) earned for each.
* A pending peer challenges expires in 3 days after sending, unless it's within the last 3 days of a season.
* All pending peer challenges will expire by the end of the last day each season, which is 31st March, or 30th June, or 30th September, or 31st December, regardless of original challenge date.
You'll earn the points according to correct answers upon expiration.