PMI stands for Project Management Institute, which is a global organization that provides certifications, resources, and networking opportunities for project managers. PMI offers various certifications such as Project Management Professional (PMP) and Agile Certified Practitioner (ACP) to help professionals advance their careers in project management. Additionally, PMI publishes the Project Management Body of Knowledge (PMBOK), which is a guidebook that outlines best practices and standards for project management. Overall, PMI plays a crucial role in promoting excellence and professionalism in the field of project management.