Which includes:
Conversations, Location, Feedback, Usage information
And specifically this clause:
"Please don't enter confidential information in your conversations or any data you wouldn't want a reviewer to see or Google to use to improve our products, services, and machine-learning technologies."
Update: *There is a Gemini setting here https://myactivity.google.com/u/1/product/bard but it does not explicitly state that it disables training, just activity history.