Feudalism, where economic power comes from control of the land and familial connection to the conquerors of the land, was broadly supplanted by capitalism, where economic power comes from control of commercial and industrial capital, which are traded openly in capital markets.

Capitalism has several features that feudalism does not:

• The most productive property in capitalism is industrial and commercial capital: the means of industrial production and trade. While land remains profitable, it is no longer the center of economic productivity; and ownership of the land does not convey the sort of dominion over its use that it did in feudalism. (Nobody thinks it’s weird to build a factory on leased land, for instance: the ownership of the industrial capital does not follow the ownership of the underlying land.)
• Shares of productive property (capital) can be freely bought and sold in capital markets. In feudalism, productive property (land) changes hands through warfare, political processes such as the elevation of new lords by a king, and familial processes such as marriage and inheritance.
• Contract law becomes supremely important in capitalism, as the productive entities (firms) are largely creatures of contract law rather than traditional rights.
• The capitalist managerial class by and large does not arise out of the families of the feudal aristocracy, and does not conduct itself according to the social rituals of the feudal aristocracy. For instance, corporate mergers are not arranged through marriage of the heirs of CEOs.
• Although this is not fully true of early capitalism, in modern capitalism workers are typically free to leave their jobs, and employers are broadly free to fire them if they are not productive. In most forms of feudalism, serfs are bound to the land and may not lawfully leave their lord’s service.

On that last point — Capitalism emerged out of colonialism. Many of the first firms traded on capital markets were colonial enterprises such as the Dutch East India Company (VOC). These firms employed slave labor and enjoyed legal monopolies on trade. This puts the lie to the libertarian claim that capitalism requires free labor and free trade. Capitalism is perfectly compatible with slavery and monopoly. For later examples see the United Fruit Company and other American colonial ventures.