A Certified Scrum Product Owner (CSPO) primarily acts as a liaison between the stakeholders and the development team in a Scrum framework. They are responsible for defining project goals, creating and managing the product backlog, prioritizing features based on market value, and ensuring transparency in project execution. They collaborate with the Scrum Master and the team to deliver high-value products. CSPOs also accept or reject work results, and facilitate feedback and changes in the project scope. Their role is crucial in maintaining a clear communication line and ensuring the product aligns with the stakeholders' expectations and market demands.