The article discusses how the concept of transaction costs, originally introduced by Coase, has become a key focus in economic theory, particularly through the work of O. Williamson. Williamson's ideas form the basis of transaction cost economics and neo-institutionalism. Different interpretations of Coase's original concept have led to ongoing discussions about its study. The paper specifically looks into Williamson's take on transaction costs to highlight unique aspects and differences from other interpretations.