Those are snow tires, EVERYBODY needs four of them on their cars/trucks, and it is a LAW that everyone has them on by December 01, although, any smart person will have them on by November 01! Past December 1st, you'd get quite an hefty fine and if in a accident, your car insurance will NOT pay for your damages.
Many also have like small 'sort of nails' or crushed coconut shells imbeded in the rubber for better traction on ice and snow (Called studded tires). In short, everybody has to buy 4 rims and 4 winter tires and we interchange them in the Spring for Summer tires and the late Fall for the Winter ones. C'est la vie ...