Here is something I've found and expanded on to describe the capitalist system.
Worth in capitalism is abstract human labour. That means, a commodity is worth as much as the standard way of making it costs in term of human labour time. This means that businesses in capitalism don't exist in order to produce some defined amount of useful goods, but rather to extract as much labour out of the workers as possible. This means long working hours, as few holidays as possible, machines to make production easier only if it is profitable.
Also, capitalism is about getting the most of this abstract human labour (worth) produced for the business, instead of the worker. This is a goal that most capitalists have for themselves, although even if you don't have the goal to exploit as much as possible, the forces of competition kind of get you to do it. This means low wages for the workers in absolute terms (less bucks) and even less in relative terms (smaller percentage of total wealth produced).
Also, a source of income for capitalists are natural resources. You can take things from nature for free, resources and so on. Capitalists, since they are about profit, and only can reproduce themselves for long times if they are only about profit, are ruthless in the way they treat nature. Considerations like sustainability, health damages and so on have to take the back seat to making a profit by exploiting nature as much as possible, with all the bad consequences we witness today.