What are some core differences between Product Manager and Product Owner? 
Because they share the same goal, it’s often difficult to draw a line between the two positions. While there are some areas of overlap, the product owner and the product manager have different responsibilities in the product management process.
To break it down:
The Product Owner is a role you play on a Scrum team. Product Manager is the job.
The Product Manager identifies market needs, overall vision, roadmap, budget, ROI, identifies features and objectives, and collaborates mainly with the marketing and business.
The Product Owner is responsible for maximizing the value of the product by creating and managing the product backlog. This person contributes to vision, solution, technology, releases, iterations, creates user stories for the development team and communicates the voice of the customer in the Scrum process.
As a Product Manager you might be doing more strategy and validation work with problem discovery in a product that has not been defined yet without the interaction with the development team much. So it is a separate cycle in the traditional linear approach.
As a Product Owner with a Scrum team, you may be more focused on the execution of solutions. The work is iterative and instead of focusing on the strategy and roadmap upfront you work with your team and users constantly to create the maximum value.