This book attempts to establish a new theoretical framework to analyze the intrinsic patterns of economic growth, structural transformation, and the shift of economic momentum in the digital economy era. The book provides a detailed discussion on the interactions between the old and new economic sectors (the limitless and limited sectors), the migration of labor and capital between different sectors, as well as the accumulation of knowledge capital, such as data, technology, and creativity. Additionally, it delves into the growth mechanisms of the new dual economy.