A tool provides a mechanical advantage in accomplishing a physical task, such as an arrow, plow, or hammer that augments physical labor to more efficiently achieve his objective. Later animal-powered tools such as the plow and the horse, increased the productivity of food production about tenfold over the technology of the hunter-gatherers. Tools allow one to do things impossible to accomplish with one's body alone, such as seeing minute visual detail with a microscope, manipulating heavy objects with a pulley and cart, or carrying volumes of water in a bucket.
The second technological stage was the creation of the machine. A machine (a powered machine to be more precise) is a tool that substitutes the element of human physical effort, and requires only to control its function. Machines became widespread with the industrial revolution, though windmills, a type of machine, are much older.
Examples of this include cars, trains, computers, and lights. Machines allow humans to Tremendously exceed the limitations of their bodies. Putting a machine on the farm, a tractor, increased food productivity at least tenfold over the technology of the plow and the horse.
The third, and final stage of technological evolution is the automation. The automation is a machine that removes the element of human control with an automatic algorithm. Examples of machines that exhibit this characteristic are digital watches, automatic telephone switches, pacemakers, and computer programs.