Stamps and mailboxes

A stamp is a small paper voucher attached to a letter or package to pay for postage. Stamps are generally issued by sovereign states, reflecting the history, technology, economy, culture, customs, and natural scenery of a country or region, and have gradually become collectibles. A mailbox is a postal facility typically located on the street or in other areas to facilitate the mailing of letters.

The unit is designed for unsupervised public use: controls are recessed or shielded, moving parts are enclosed, and the interface is operable by a child of about six with no instruction. Where a screen is used, the language can be switched without changing the hardware, and the content can be replaced on site.

With the development of the Industrial Revolution and transportation technology in modern times, the information transmission that was originally monopolized by the state gradually gave rise to a postal department specialized in delivering letters and items, giving rise to the postal industry. Stamps emerged as specialized identifiers for letters and items being conveyed. It is both a label for mailing items and a basis for pricing. At first, it existed as a mark, but later people designed its shape and content specifically for anti-counterfeiting and aesthetics, giving the content of the ticket a sense of the times and cultural connotations. At the same time, different tariff denominations can be set according to needs for ease of use, thus enabling stamps to appear in sets from single sheets to later versions.