Postal code usually consists of Arabic numerals, which represents the special code of the post office that delivers mail, and is also the communication code between residents and units within the delivery range of the post office. Postal code is a special code for postal communication to realize mail sorting, and it is a necessary tool to realize postal modernization. The ultimate goal is to improve the speed and accuracy of your letter delivery.

Postal code is a scheme to realize automatic sorting of letters, because computers can't recognize Chinese, but they can recognize numbers. By coding each area, you can quickly sort it by computer. Of course, the finer you write, the better.

China postal code adopts four-level six-digit coding structure. The first two figures represent provinces (cities, autonomous regions); The third digit indicates the postal area; The fourth digit indicates the county (city); The last two digits indicate the office.

Geographical environment of Tianjin

Tianjin is located on the west coast of the Pacific Ocean, in the north of North China Plain, bordering Bohai Sea in the east, Yanshan Mountains in the north, and facing the lower reaches of Haihe River across the sea. It is the traffic throat of Beijing's railway to Northeast China and East China and the port of ocean transportation. Known as the gateway of rivers and seas and Kyrgyzstan, it has a vast hinterland, radiating to three provinces, cities and autonomous regions in North China, Northeast China, Northwest China/Kloc-0, and facing Northeast Asia externally. It is the largest coastal open city in northern China.

Tianjin is located between east longitude116 43 and north latitude118 04, with a total area of 1 1966.45 square kilometers, and the city center is located at 65438+ east longitude. North-south length 189 km, east-west width 1 17 km, land boundary length1/37 km, coastline length 153 km.

The above contents refer to Baidu Encyclopedia-Tianjin.