Radio Frequency Identification is a technique that uses short range radio transmissions for collecting information on people, animals, and products. This information may include identity, position, time, or financial transactions. Unlike barcodes which only identify product groups, RFID tags can have a unique number for each product. Identification is performed in milliseconds and line-of-sight is not required. There is no contact between the tag and reader which allows multiple tags to be read simultaneously. The tags can also work in harsh environments or be implanted under the skin for pet identification and livestock tracking.