The challenges "description" (actually explains the challenge)
A number indicating the "goal" (see AccountChallenge.progressNum)
The challenge's ID
If this challenge slot has been claimed
If this challenge slot has been completed
If this challenge slot has been rerolled already and cannot be rerolled again
The challenge's "name" (playful and does not explain challenge)
A number indicating "progress". In a challenge with kills, this would be the number of kills so far. Varies heavily depending on challenge type.
The raw challenge as sent by the server. Challenges does a bit behind the scenes to "clean up" the challenge and make information on it a bit easier to understand.
The number of eggs rewarded when the challenge is completed & claimed
The Challenge that is in Challenges.list