An address range is the span of house numbers a street-range register publishes for one stretch of a street — 100 to 198 on one side, 101 to 199 on the other — which places a number on a street without listing the building itself.
What Spaw answers
match_level: range means a US address whose building no premise register carries fell inside a range the Census Bureau's TIGER/Line tables publish for that street in that ZIP; confirmation.house_number reads range and exists stays null, because a range says the number is plausible, not that a building stands there. A street the table knows whose number falls outside every published range answers match_level: street with the number_out_of_range weight of +20. A street the table does not know answers none with no weight: the table is declared partial, since not every edge carries a range and a street on a ZIP boundary can be filed under its neighbour's ZIP alone.
What it is not
It is not a delivery-point check. The postal service's own record of whether post reaches a number is licensed data that stays behind is_deliverable; a range is the public map's idea of which numbers a street segment could hold.