You must have seen bar-coded items in supermarkets. There are about 250 types of barcodes that have been designed till now. They may be 1D or 2D. Those which you observed on the goods are referred to as linear barcode. Standard of these barcode are published by AIM and are currently in progress at ISO.
Barcodes consist of small images of lines (bars) and spaces affixed to retail store items, ID cards and postal mail to identify a particular product number, person or location. A barcode reader uses a laser beam that is sensitive to the reflections from the line and space thickness and variation. The reader translates information from the image to digital data and sends it to the computer for further process.
2. Radio Frequency Identification (RFID):
This technology acts as the base in automated data collection, identification and analysis systems worldwide.
RFID obtains information on an item without making direct contact with the item. Depending on the technology variation used, reading and writing distances can vary from few millimeters to several meters.
RFID systems comprises of three components: an antenna, a transceiver and a transponder (the tag). The application area of RFID includes livestock identification and Automated Vehicle Identification (AVI) because of its capability to track moving objects.