Each note belongs to its own group.
When program starts for the first time there is only one group - "General". Every new note is created in this group by default.
You may add, modify or remove groups at PNotes Control Panel. Each group may have it own settings, include icon, background and caption font color (for skinless notes), skin (for skinnable notes) and font color.
Any note created in specific group or transferred to it inherits group settings. You may change note's group or by simple drag-n-drop on PNotes Control Panel or by using note's "Rename" menu and choosing desired group in combo box.
If any group is selected on PNotes Control Panel, then new note will be created in this group, although you may always change the group when you save note.