A label is a small device for storing and transmitting information. It consists of a microchip and an antenna with which it transmits and receives information. There are tags that have a built-in power source (active tags), but the bulk of the tags used today do not have a built-in power source (passive).
A unique number and / or a certain amount of user memory is stored in the memory of the tag. When a tag enters the reading zone, this information is received by the reader (reader) - a device capable of reading and writing information in the tags, and transmitted to the computer for further processing.

Labels can be of various types, depending on the field of application and objectives of the enterprise: from small flexible labels that mark individual goods to packaged plastic labels for marking metal containers. Tags may differ in size, shape, materials from which they are made, the method of attachment, memory size, operating frequency, reading range.
The reader contains a transmitter and an antenna through which the electromagnetic field of a certain frequency is radiated. The radio-frequency tags that fall within the range of the reading field "respond" with their own signal containing useful information (for example, product code). The signal is captured by the antenna reader, the information is decoded and transmitted to the computer for processing.