The Vault holds extra rewards players earn throughout the Season. Once a player reaches 1,100 Season Challenge Points, the Vault will continue collecting Season Challenge Points from Daily Challenges for even more rewards.
Rewards from The Vault are collected when the Season ends on the 1st of every month. Then the Vault resets for the next Season.
To view your Vault, click on Challenges in the upper left corner of the Games screen, and then click on the Perks tab.
Here, the Season Perks and Season Vault are displayed:
Please Note: The Season Perks are for VIP players only.