Section reordering basically means to arrange the section as per our requirement. in order to proceed with this section, you need to drag the section on top or bottom where you need it. when you will drop any section top or bottom your front view will change according to customizer values.
For Section Re-ordering, you just need to simply drag-and-drop options into any order as per your wish.
In order to proceed with Section Ordering.
Go to Appearance >> Customize >> Theme Settings >>Section Ordering