Machines help farmers to grow food for people in the world. Tractors are very important because they push, pull and lift other machines. Most tractors have large back wheels so they can be driving over rough ground and for grip when pulling heavy machines. Most tractors have large back wheels so they can be driving over rough ground and for grip when pulling heavy objects.
Many tractors have four wheel drive to get extra grip on the hills and in wet conditions.
A lot of tractors come with cabins so the farmer can work in wet or on cold days. Most tractors come with a P.T.O. shaft so that when it turns it operates balers. Also tractors can come with linkage to lift round bales. Tractors also can come with a hydraulic system which makes oil pressure to lift ploughs up. If you have linkage most tractors which do have weights to stop it from flipping up.