The term implies a social contract on establishing and maintaining ownership in relation to such items which can be invoked with little or no effort and expense on the part of the owner. The concept of wealth is relative and not only varies between societies, but varies between different sections or regions in the same society. A personal net worth of US$10,000 in most parts of the United States would certainly not place a person among the wealthiest citizens of that locale. However, such an amount would constitute an extraordinary amount of wealth in impoverished developing countries.
The organizing principle behind this grouping, appropriate economic units, is relatively simple: if the activities are located in the same geographic area; if the activities have similarities in the types of business; or if the activities are somehow interdependent, for instance, if they have the same customers, employees or use a single set of books for accounting.
The doctor or lawyer, for instance, could use her or his income to invest in a medical start-up or buy shares of medical companies he understands such as Johnson & Johnson. Over time, the nature of compounding, dollar cost averaging, and reinvesting dividends can result in her or his portfolio generating substantial passive income. The downside is that it can take decades to achieve enough to truly improve your standard of living. However, it is still the surest path to wealth based on the historical performance of business ownership and stocks.