How does the AUT/190 setting on my Buderus boiler work?

I just moved into a new house with a Buderus gas boiler (lucky me!). Does the AUT / 190 setting on the aquastat actually do anything "automatic" or does it just set the boiler temperature to 190 degrees F? Does it somehow compensate for outdoor temperature or settings to, say, lower the boiler temperature on warmer days and raise it on colder ones?