In an agrarian society most people are working on small plots of land growing food and/tending animals. Their labor combined with the natural resources is enoug

In an agrarian society most people are working on small plots of land growing food and/tending animals. Their labor combined with the natural resources is enough to create food for their families and a little bit left over. They take that little bit left over and trade it to a guy that makes clothing, and a guy that makes tools. All the goods and services in the whole country don't amount to all that much -- enough food to feed everyone plus some clothes and tools. Now move to the industrial agricultural age. The same food (better really) that it used to take 90% of the labor of the country to grow now can be done by 5% of the people. Instead of having only enough surplus to support a few guys making clothing or building tools, most of society can go off and find things to do with their time to trade to the farmers for food and to each other for whatever everyone else is doing. Now all the good and services of the country not only include a wide variety of food, clothing, and tools, but it also includes concerts, amusement parks, computers, dishwashers -- all of which can be traded for the very same bushels of corn or herds of cattle that the agrarian society was producing. All of this is very simplified but it should give you the basic idea. Bill Gates can give the global poor money and they can use that to import goods and services made elsewhere, but that's just a temporary change. If you really want the societies to be richer, you need the people in that society to be doing things with their time that are of great value to others. That's what increases the total amount of wealth in the world.