Booty is the main currency in Oasis.
You can get Booty by completing quests, coming online, and finding it in-game. You can also buy Booty with Rays at an ATM. You cannot get a refund for booty (exchange them to get your Rays back) so make sure you buy the correct amount.
You can use Booty to access in-game features and buy clothing and objects.
You can view your Booty balance in-world underneath your mini-avatar