You can see what is gathered by opening about:telemetry. That page also has links to dashboards derived from telemetry data. You can read the policies that app

You can see what is gathered by opening about:telemetry. That page also has links to dashboards derived from telemetry data. You can read the policies that apply to what data may be collected at https://wiki.mozilla.org/Firefox/Data_Collection https://wiki.mozilla.org/Firefox/Data_Collection