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 from the day the Challenges are sent, unless it's within the last 3 days of a season.
* All pending peer challenges will expire by the last day each season, or the last day of each term, or the day before a new term starts, which is 2nd March, or 18th March, or 31st March, or 24th June, or 30th June, or 24th August or 8th September, or 30th September, or 2nd November, or 31st December, regardless of original challenge date.
You'll earn the points according to correct answers upon expiration.