Investment science mainly analyzes problems from the perspective of market investors, trying to find overvalued or undervalued financial instruments/derivatives in the capital market through various pricing models and pricing principles, so as to make corresponding operations and make profits.
The management of commercial banks mainly analyzes the problems from the perspective of commercial banks, the most important financial intermediaries. Analyze the bank's capital structure, risk control, profit model and so on. Among them, risk control is particularly important.
Corporate finance mainly analyzes the company's capital structure, financing methods, working capital management and project investment from the perspective of company managers.
To sum up briefly, if the financial system is composed of four parts: fund demanders, fund suppliers, financial intermediaries and financial markets, then investment science, commercial bank management and corporate finance understand the financial system from three different standpoints respectively.