1. Physical label Physical label is a brief label used to indicate the product name, weight, volume, purpose and other information of the item. There are traditional printed labels and modern barcode printed labels. Scope of application: Packaging: shipping mark labels, postal parcels, letter packaging, transportation cargo markings, envelope address labels. Electrical appliances: mobile phone internal labels, various electrical appliance labels, laptop computer labels, mechanical and electrical product labels. Commodities: price tags, product description labels, shelf labels, barcode labels, pharmaceutical labels. Management: book tags, vehicle inspection tags, security inspection tags, property tags. Office: document labels, archive storage labels, various items and stationery labels. Production: raw material labeling, processed product labeling, finished product labeling, inventory management labeling. Chemical industry: labeling of paint materials, packaging labeling of gasoline and engine oil products, and labeling of various special solvent products. Others: anti-counterfeiting labels[2], encryption labels, anti-theft labels. Jewelry: Jewelry tags, tags that are not easy to attach to products. Clothing: clothing tags, washing labels. Airport: boarding pass, luggage tags. Tickets: train tickets, long-distance bus tickets. Others: parking lot tickets, highway toll tickets. 2. Network tags Network tags (tags) are a way of organizing Internet content. They are highly relevant keywords. They help people easily describe and classify content for easy retrieval and sharing. Tags have become an important element of web 2.0. . Tags transfer content organization rights from website administrators to users, fully embodying the bottom-up, user-participation characteristics of web 2.0. If you have visited flickr (pictures), technorati (blog), del.icio.us (delicious bookmarks) and other web2.0 websites, you will find that the website uses tags to display content, and users use tags to describe content. and search related content. The "open classification" used by Baidu Encyclopedia is also a form of tags. 3. Electronic tags Electronic tags are also called radio frequency tags, transponders, and data carriers; readers are also called reading devices, scanners, reading heads, communicators, and readers (depending on whether the electronic tag can rewrite data wirelessly). The spatial (contactless) coupling of radio frequency signals is achieved through coupling elements between the electronic tag and the reader; in the coupling channel, energy transfer and data exchange are realized according to the timing relationship. Electronic labels are a tool to improve identification efficiency and accuracy, and this technology will completely replace barcodes. RFID radio frequency identification is a non-contact automatic identification technology. It automatically identifies target objects and obtains relevant data through radio frequency signals. The identification work does not require manual intervention and can work in various harsh environments. RFID technology can identify high-speed moving objects and identify multiple tags at the same time, making the operation quick and convenient. RFID electronic tags are a breakthrough technology: "First, they can identify a single, very specific object, rather than just one type of object like a barcode; second, they use radio frequency and can be read through external materials. To obtain data, barcodes must rely on lasers to read information; thirdly, multiple objects can be read at the same time, but barcodes can only be read one by one. In addition, the amount of information stored is also very large. ”