As Elon Musk works to prove that he can make Tesla profitable and his Autopilot feature safe, it’s worth understanding the difference in how Tesla is developing self-driving car technology versus other companies.

These differences relate in part to a potential advantage that Tesla has over other self-driving car developers: It has sold hundreds of thousands of cars—each connected to the internet—so it can use the experience of those cars to gradually “train” Autopilot software and learn what is working and what is not. Improvements to the software can be sent wirelessly anytime. (See article on Autopilot’s leaders and Mr. Musk’s personal testing of the software here.)