The round one is an avatar upgrade, such as additional strength or more currency collection. The round discs can be used in both playsets and toy box modes.
The hexagonal discs can onyl be used in toy box mode and bring in additional 'toys' or world customisations that change textures within worlds.
How They Work:
POWERS, GADGETS, THEMES & FLYING ELEPHANTS
DISNEY INFINITY Power Discs can be used to improve and enhance the DISNEY INFINITY experience in a multitude of ways. Circular Power Discs are used to grant your character special power ups that can be used in Play Sets and in the Toy Box. Hexagonal Power Discs unlock special gadgets, vehicles, and themes to allow for even more personalization in the Toy Box. Different combinations mean different results, the possibilities are endless!