An object is a statistical parameter typically corresponding to the application of an aggregation function (or more complex statistical analysis functions) to specific collections of units of analysis.
The folder Objects contains the hierarchy of statistical objects that can be selected, that is corresponding to statistical tables available in the system. During the selection process the list is updated to be maintained consistent with the selections already made.
The symbol near the name of an object denotes a selectable (by mouse click) object. A selectable object may or not have 'children', i.e. objects more specific than the object itself. A folder symbol near the name of an object denotes instead a container of other objects and cannot be selected. A folder object may contain more specific folder and/or selectable objects.
Clicking on the symbol the 'children' of a (container or selectable) object can be displayed.