Software development kit (SDK)

Think of a robot as a car with the hood welded shut. You can drive it where the pedals let you go, but you cannot change the engine. A software development kit is the maker handing you the key to the hood.

With one, a university lab can write code that tells the robot’s joints exactly what to do, and plug in their own cameras or artificial intelligence. Without one, the robot only does what the factory programmed: walk, wave, dance, follow a handset.

This matters for price. On some Chinese humanoids the basic model and the developer model are close to the same hardware, and most of the extra cost buys you that access.