The biggest advantage that a tractor has over a team of horses, (or mules, or oxen, or whatever your great-grandpa used) is it's ability to transmit power to an implement.  This is accomplished by way of the Power Take-Off shaft, or PTO.  There are different types of PTO systems in use today, and it is important that you select the correct type to accomplish the tasks you need to do, in the most efficient, safe manner.  Keep in mind that there is no "perfect" PTO system.