RFID is a technology that uses radio waves to communicate between devices. RFID tags are often used in inventory management, and can be found in items such as clothing, books, and even pets. When an RFID tag is placed near an RFID reader, the reader emits a radio signal that energizes the tag. The tag then responds by transmitting its unique ID number to the reader. The reader decodes the ID number and sends it to a computer, which can then look up information about the tag (such as what product it belongs to). RFID tags are made up of three parts: an antenna, a chip, and a substrate. The antenna is responsible for receiving and transmitting radio signals, while the chip stores the tag's ID number. The substrate (usually made of plastic or metal) provides support and protection for the other components. RFID tags come in two main types: passive and active. Passive tags do not have their own power source, so they must be energized by an external signal in order to transmit their ID number. Active tags, on the other hand, have their own power source (usually a battery) and can transmit their ID number without needing to be energized by an external signal. RFID technology is used in a variety of applications, including inventory management, security, and tracking. RFID tags are often used in inventory management systems to keep track of products as they move through the supply chain.