The “PAA” indicator indicates that the sensor can connect to PurpleAir servers. The sensors will send their measurements to these servers. This would include measurements like particulate matter counts, temperature, pressure, humidity, VOCs, timestamps, etc. Much of the data that appears in the serial output is what is sent to our servers.
The data sent to our servers does not change for a registered vs. unregistered sensor. Instead, the registration connects the data from a sensor to a map location.