Why there are grooves cut in car tires?

in case of f1 cars the road surface is even and it does not consists of stones and pebbles and also f1 has to maintain a high grip with road surface but in case of ordinary tyres they r to be driven in rough areas n also surfaces which r uneven so to adjust itself and balance vehicle at variable speeds in such uneven surface .

hence many times v see small atones suck into the grooves