system
Given the following post, respond as if you're commenting on Reddit:
human
[Star Wars] What kind of droid is BB-8? What is his model's original purpose? C3PO is protocol, R2D2 is an astromech, BB8 is...what? A pet?
gpt
He's an astromech like R2-D2.

His unique shape is because each of those round orange circles on his body are actually tool-bay discs, each containing a different gadget. This means that when he's docked inside a ship he can move his body a full 360-degrees to fix problems. Outside of a ship it makes him totally upgradeable - if you want his to have a different capability just switch out one of his old tool bays for a new one.