Let's say that you make tables and chairs. That's your labor. Using straight barter, you can only trade your goods for other goods. Works alright in medieval times within your shire. Doesn't get you iPhones or cars or even pay the electric bill. Capitalism is simply introducing the idea of money as an intermediary between the barter. You sell your goods to Jim. Then take the money and buy goods from Bob. Bod didn't need your goods. That's the simplest form and most rewarding. We all have a choice on what to do with our labor. Working for someone else is easier and less risky but comes at a cost. There's really nothing more to it. We the people to to make more controls on corporations to stop the separation of wealth and restrict the shareholder goal of profit over everything else. Every system needs controls especially when society advances.
You are wrong. Capitalism is not money exchanging. Capitalism comes from capital. That is money being used in a way that does not return goods or services but more money that can then be used for further capital.
In the interest of further capital keeps the wealth has several class based effects. It is easier to gather more capital when workers are not aware of each other, do not know how much their labor is worth, and blame other workers or themselves for their position. The most important part of society to the capitalist is themselves. They do not see labor as important of necessary to the process or the laborer. The most ideal way to gather capital is slavery and every advance in technology and policy, from a capitalist, used to cut out more workers and bring more slavery.