The document discusses electronic noses, which are devices that mimic the human sense of smell. It describes electronic noses as consisting of an array of electronic sensors and a neural network for pattern recognition. The document then compares the biological nose to an electronic nose and discusses their similarities. It explains the need for electronic noses due to limitations of human sniffers. The working, principle, and applications of electronic noses are outlined, including uses in food, medical, environmental, and other industries. The document concludes that while not as sensitive as biological noses, electronic noses can perform analyses faster and at lower cost than human sniffers.