Active tuning is where the ECU adjusts tables in the ECU as you drive, without the need for a laptop or the FlashPro to be plugged in.
Fuel tables and air flow meter tables can be tuned in this way.
For example, here is the short term fuel trim from driving a fixed route, while using active fuel tuning. The distance of the short term trim from 0% shows the quality of tuning. As the samples show, the magnitude of the short term trim decreased over time from the ECU activly tuning the fuel tables.
Baseline fuel trim
After active tuning 5 minutes
After active tuning 15 minutes