1. Introduction and background; 2. Carl Menger and the structure of production; 3. Böhm-Bawerk's labor arithmetic; 4. Austrian capital theory (ACT) and Austrian business cycle theory (ABCT); 5. Hayek's capital theory; 6. Ludwig Lachmann's kaleidic world of capital heterogeneity; 7. Ludwig von Mises's 'capital from a financial perspective'; 8. Capital in the aggregate production function; 9. Capital in a simple financial framework; 10. Conclusion – the entrepreneur adds value by capitalizing resources.