Generally, a Product Manager’s primary responsibility is to analyze the market, competitors, customers, external environment, lead and plan activities related to a specific product or product line. Product, is usually referring to any form of products or services.
There are too many textbooks available in the market that touches on marketing management, strategy or even business management. But most of what we learned from books as well as from business schools are general introductions to marketing management or high-level strategic concepts, but not the how to perform day-to-day responsibilities of owning and managing a product or product line.