A Product Owner is a key role in agile project management, primarily responsible for defining the vision of a product. They prioritize the product backlog, which is a list of tasks and features that need to be completed, ensuring that the most valuable items are addressed first. This role acts as a bridge between the development team and stakeholders, gathering requirements and feedback to guide the product's development. In addition to prioritizing tasks, the Product Owner collaborates closely with the Scrum Master and the development team during sprint planning and reviews. They ensure that the team understands the goals and requirements, helping to maximize the product's value and align it with customer needs.