I have bounced back and forth in my career between Product Management and Project Management. This is further complicated by the use of (and differences with) Program Management.
Some time ago I saw a blog post that I think does a generally good job at drawing the distinction, product-management-vs-project-management
I refer to it occasionally, especially in situations like my current one where I am the project manager for one project and the product manager for another. Mentally switching hats (and perspectives) is a challenge.
I've been looking for good sources that discuss how Product Managers and Project Managers can improve the effectiveness of their interactions. Anyone with ideas, please let me know. The Agile courses I've taken talk about the separation of duties but rarely do a good job at characterizing a process by which these two roles can most effectively communicate.