After identifying the place at which the document has to be sent, it is necessary to know the exact code of that country or city, which can be done with the help of a zip code. Zip code is basically a zoning improvement system, started by the United States and mostly associated with Americans. It is also known as another version of postal code which consists of 5-9 characters. Zip Code does not contain any alphabet. It just consists of numbers or a 5 digit code. And each city where the facility of mail is present has been given the code.