What is a ZIP code?

Many people ask: what is a zip code? Here is the answer.

It all depends on ZIP code stampZIP code is a special number in the postal system used by the USPS (United States Postal Service) since 1963.
The ZIP acronym means Zone Improvement Plan.
Every ZIP code designates one delivery point in the USA area (for example one town or quarter of a city).
It may be also U.S. dependency and U.S. military unit stationed outside of the United States.

Every ZIP code includes the five digits, that determine a location in the USA.