This chapter explores key concepts such as diminishing returns, capital accumulation, economic progress, and the structure of production. It examines Böhm-Bawerk’s idea that roundaboutness—extending production time—enhances productivity. Hayek’s triangle is introduced to illustrate the multi-stage production process. Additionally, the chapter critiques the standard aggregate of the Gross Domestic Product as an insufficient measure of economic activity and refutes the Keynesian “paradox of saving,” emphasizing savings as a driver of long-term economic growth and wealth creation.