CAPITALISM!

capitalism is broken up into many different parts, but overall what it means is that its "an economical system in which good services are produced , distributed,and consumed though the mechanism of free markets". meaning that its all about how products are bought and sold and the logic behind it . another point to add in would have to be that its all about the "free market" and "private property", meaning that it all depends if its free market and anyone can sell the product , or if its private and you have to have the right to sell the product.
the three main parts of capitalism is : land , labor , and capital . meaning that the land is literally the land that you sell your product on ( aka the store, the street, the grass). the labor is who you choose to MAKE sell the products for you , or the labor that you do to sell the products or to produce your products, and then the capital is the stuff that you use to sell you items like signs, advertisement, and then the wealth comes in !
the wealth is when you get profit from the products you sold and are able to increase your profit by upgrading ! the most fun of it all ! it all turns into a cycle sell,profit,upgrade,MORE profit, sell upgrade, EVEN MORE profit.. etc etc. its a way to get rich !
the main objective of the seller would be to make the most money possible while spending the least amount possible. meaning that he wants to buy the product for a cheap amount of money and make the buyer pay extra , so he gets profit. but then its not all up to him , he always has to relate back to the supply and demand chart. the supply and demand chart lets you know the highest price you can sell the item for and the lowest amount of money the buyer will pay for the product, which is the market price. you have to revolve it all around the market price which ends up changing here and there, it all depends on the supply and demand if it shifts or not !
now going a little off topic, theres always going to be competition, if theres a free market, there will be way more competition because you'll have more competitors trying to sell along side of you while if its private , you don't have as much.
thats when the invisible hand comes in! the invisible hand is when you put your own interest ahead of your self so that you do stuff automatically , its kind of like your instincts. people use the invisible hand in these situations because they are competing with others so their first instinct is to do BETTer then their competitors and they do it without thinking about it . if one person is selling a coffee for one price, you sell yours with a donut for the same price etc. its all about the competition!