A field is one or more areas or the whole image in an analysis.
You can make statistical evaluations over field results of the following calculations: Number(of)Objects, AreaRatio, Area(of)Objects and MeasuredArea.
Add-> inserts the selected function in the list of the active functions.
All-> inserts all the functions in the list of the active functions.
<-Remove deletes the selected function from the list of the active functions.
<-All deletes all the functions from the list of the active functions.
OK confirms and saves the selection.
Relatively to the active function(s), basics statistics (Mean, Standard Deviation, Maximum and Minimum) are calculated over fields selected in Results: All Fields.