By achieving challenges and missions or by finding hidden chests, you can loot all kind of chips : skills improvements, pets, pet food, graffities…
Except graffities, they all have various quality levels. The bonuses that are granted by the chips varies with their quality level.
Each character have its own skill tree where you can fill slots with the chips you gathered.
You can change your chips whenever you want. This makes characters’ customization even more user-adjustable. If you want to change your chips, simply use one of the many E-Swap terminals (kind of ATM) available in the city