Okay, here’s how wealth is created in a capitalist economy:
Bob wants to build a house. He’s very good at carpentry, but he’s lousy at bricklaying. He can do carpentry at the rate of one house per month. But bricklaying takes him three months to do a house. And roofing takes him two. So if Bob builds his house by himself, it will take him six months.
Joe is great at bricklaying, and can lay bricks for a house in a month. He’s just as good at carpentry and rooflaying, because he’s very smart. So he can build a house in three months.
Between the two of them, they can build three houses in six months (Joe can build two, Bob can build one).
Now, Bob goes to Joe and says, "Tell you what, why don’t you lay my bricks, and I’ll do your carpentry? But Joe isn’t interested, because he gains nothing and has to travel, take on risk of the other guy not being happy, etc. So he says, “Tell you what - I’ll lay your bricks for you, but in return I want you to do the carpentry on my next two houses.” So for Bob, this is a good deal too, since he can do two month’s of labor and in return Joe will do what would take Bob three months. Joe also gets two months of labor from Bob, at the cost of only one month of his own.
So now, after six months there are three houses, plus framing for two more (Bob’s payment to Joe, plus the extra framing he could do with his spare month), The new framing would not have existed had Joe and Bob not agreed to exchange services.
Now, it doesn’t do Bob and Joe much good to do framing for two houses that don’t exist yet, so Bob gives Joe an IOU for the framing he’s promised to do. Joe can then take that IOU and trade it to someone else for whatever he wants.
As you start adding more people to the equation, and everyone is giving each other IOUs for goods, it starts to become a real pain. You’ve got an IOU for bricks, and you meet a guy who will make you a chair. But he doesn’t want bricks. So you have to start looking for intermediaries. So to get rid of this hassle, you create money, which is essentially a generic IOU. Now you don’t have to worry about who wants what - you give the chair guy money, and he can go use it to buy what he wants. Now the system is more efficient.
There is nothing magic here - the free market is just a gigantic clearinghouse of goods and services. It allows people to organize together for efficiency, and the price system communicates what people are willing to pay for various services. Wealth is created because people can specialize on what they do best, or organize together to create things they couldn’t create on their own. Everyone has their own comparative advantage - some are smarter, some are better with their hands, some might live near natural resources. The free market allows people to trade their comparative advantages and improve overall efficiency, which creates even more wealth.
The rest is just details. (-: