A Product Backlog is a prioritized list of features, enhancements, and fixes that need to be developed for a product. It serves as a dynamic repository where stakeholders can add, remove, or modify items based on changing requirements and feedback. The backlog helps ensure that the development team focuses on delivering the most valuable features first. In the context of Agile methodologies, the Product Backlog is regularly reviewed and updated during sprint planning sessions. This allows the team to adapt to new information and maintain alignment with the overall goals of the project, ensuring that the product evolves effectively over time.