Disaabled=Self Explanatory.....
if not turn back now and do not change any settingsAuto=Enabled with optimized values for regulation (exacctly who calls it optomized can be questionable at times)
Enablled=Enabled but you will find another setting that allows the user to define regulation values.

“Two things are infinite: the universe and human stupidity, I'm not sure about the former” ~ Albert Einstein