Tread, traction and temperature ratings are known as the Universal Tire Quality Grading (UTQG) standard. They represent comparative ratings based on tyre performance when tested under controlled conditions on specific government test courses
Treadwear: The wear rate of a tyre. The higher the number, the better the treadwear compared to other tyres in the test. For example, the wear rate of the Bridgestone Potenza RE003  is 220.
Traction: The ability of a tyre to stop on wet payment. This rating carries a code of, "A," "B," or "C", with "A" signifying the highest traction efficient.
Temperature: A tyre’s resistance to heat generation. A tyre’s heat resistance is determined by its ability to dissipate heat. This rating carries a code of "A," "B," or "C," with "A" signifying the highest level of heat dissipation.
It is important to keep in mind that these ratings are determined by each manufacturer. While they are a great tool for comparing similar tyres from the same manufacturer, results when comparing tyres from different manufacturers may be inconsistent.
Real life tyre performance is also dependent on road conditions, the type of vehicle and how your vehicle is driven. These variables may not be accounted for in a controlled testing environment.