I’m not trying to be obtuse but I genuinely don’t understand what the difference between the terms ”full self-driving” and “autonomous driving” are. They’re synonymous to me, and I have to imagine they are to the average person.

Tesla explains it as:

Autopilot is an advanced driver assistance system that enhances safety and convenience behind the wheel. When used properly, Autopilot reduces your overall workload as a driver. Each new Tesla vehicle is equipped with 8 external cameras, 12 ultrasonic sensors and a powerful onboard computer provide an additional layer of safety to guide you on your journey. Model 3 and Model Y built for the North American market have transitioned to camera-based Tesla Vision, which are not equipped with radar and instead rely on Tesla’s advanced suite of cameras and neural net processing to deliver Autopilot and related features. Model S and Model X continue to be equipped with radar.

Autopilot comes standard on every new Tesla. For owners who took delivery of their cars without Autopilot, there are two packages available for purchase, depending on when your car was built: Autopilot and Full Self-Driving Capability.

Autopilot and Full Self-Driving Capability are intended for use with a fully attentive driver, who has their hands on the wheel and is prepared to take over at any moment. While these features are designed to become more capable over time, the currently enabled features do not make the vehicle autonomous.

That's bullshit. Name it something accurate. Don't give it a name that is an outright lie and then correct yourself in the fine print.