The Daily Task feature for Brave Frontier Global is another way of giving back FREE in-game items to all of you for your great support for the game. Basically each day, you will be given an optional set of required missions or quests that you need to finish within the same day. In return, you will be given Brave Points for Milestone rewards. That's not all, those Brave Points are usable to trade-in for some awesome additional reward. One of which is a Summon Ticket which will let you summon using the Rare Summon Gate.
If you want to know more details about the Daily Task feature, then you can read this article.