The Regions page represents the item type for the 'Region' (also known as province, or state) field, which is referenced in physical addresses. Databases come pre-configured with a standardized list, but this list can be modified.
First, select the appropriate country within the "Country" dropdown above the grid. Regions can only be managed for countries which have "fixed regions" enabled.
To add a region, click the "Add Region" link at the top of the page. To manage an existing region, click "Edit" within the grid next to the associated region. Unused regions can also be deleted from the edit page.