The primary difference is the obstacle avoidance system each one uses. The T8 (no AIVI) uses the front 3D laser sensors Ecovacs calls “TrueDetect” that fires infrared signals to detect objects upfront. In comparison, the T8 AIVI has a single-lens camera with artificial intelligence (Artificial Intelligence Vision, hence the term AIVI). An AI software processes all the images it captures to determine an obstacle and which isn’t.