ZIP code is a postal code system used by the United States Postal Service (USPS). The USPS assigns a unique five-digit code to each address in the United States to facilitate efficient and accurate mail delivery.
The first digit of the ZIP code represents a broad geographic area, while the following two digits represent a more specific region within that area. The last two digits identify the post office or delivery area within that region.
In addition to the five-digit ZIP code, there are also ZIP+4 codes, which include an additional four digits that further narrow down the delivery area.