This question is about project manager certifications.
A PMI certification is a certification for project managers that ensures someone is ready and qualified to meet the demands of a job in project management. There are many different PMI (Project Management Institution) certifications, for many different skill and experience levels.
The most common PMI certification is PMP certification, which is Project Management Professional certification. This is the gold standard in project management and is offered through the Project Management institution. There are other certifications that focus on different experience levels as well, as all PMI certifications help to enhance and accelerate any career.