What is itil certification?

Well, ITIL is a Certification that is for the IT Service Industry. At a high level, it is a framework for delivering high quality IT Services. According to the official ITIL Website, the definition for ITIL is:

"ITIL is the most widely adopted approach for IT Service Management in the world. It provides a practical, no-nonsense framework for identifying, planning, delivering and supporting IT services to the business."