The article includes the background of appearance and diffusion of the concept “entrepreneurship” from the times of Roman Empire to our times, as well as standpoints on this matter of French, English, and Russian economists of XVI-XX centuries. Moreover, definitions of entrepreneurship by A. Marshall, J. Schumpeter, G. C. Guins are analyzed in detail. The authors are critical about the definition included in the Civil Code of the Russian Federation (article 2.1.), which states systemic receiving of profit as the personal and/or group purpose of the entrepreneurship, while the purpose of this kind of activity – the development of public production – is not included. The article outlines the experience of Russian entrepreneurs of the beginning of the XX century, who, having combined personal and public interests, in a short historic period brought Russia to the number of the most developed countries according to a number of indices. The article provides definitions of different scientists, as well the authors’ own broader understanding of the term “entrepreneurial activity”. The authors suggest their own classification of different kinds of entrepreneurial activity and their significance. The article draws attention to the qualities that the entrepreneurs must have and the necessity of increasing social-economic efficiency of the entrepreneurial activity.