The ability of intellectual resources to form capital, generate and promote new knowledge in the economy, in the sphere of production and consumption calls for a more in-depth study of their role in the economy and industrial production. The development and creation of new technology helps to improve the quality of life of the population. The formation and use of intellectual capital in an innovative type of economy activates high-tech developments, increases the effectiveness of the commercial use of intellectual property. The intellectual abilities of individuals, the desire for continuous development, professionalism, and creative initiative contribute to the continuous updating of technologies and the construction of a new society based on innovation. The value created by companies is increasingly generated by intangible assets, which are understood as knowledge, know-how, innovation potential, license agreements, organizational structure and culture, and other resources for the company’s development. The ability of an enterprise to manage these types of assets is critical for its prospects in the knowledge economy. In the scientific literature, the authors distinguish various definitions of intellectual capital. A number of definitions of intellectual capital and its structural elements is growing, making it difficult for specialists to discuss them due to the fragmented terminological apparatus. This determines the relevance of this work. The aim of the study is to identify the most significant definitions of IC that most effectively affect the development of a successful business, as well as to optimize and structure of the existing definitions to streamline the terminological apparatus of research in the field of intellectual capital. The paper shows that in the ranking of the most frequently used terms, human capital, structural capital and relational capital occupy the top positions. We give alternative definitions for them and disclose the modern concepts of digital capital. We propose a classification of the types of intellectual capital taking into account the dominant influence on the effectiveness of the development of a competitive business. The results reflect the role of know-how, technological changes, digital technologies in the structure of intellectual capital.