The Project Manager Competency Development Framework (PMCDF) of the Project Management Institute (PMI®) describes the knowledge, performance and personal competencies needed to manage projects effectively. The Practical Certification Programme (PCP) supports your development in all three dimensions.
Knowledge refers to what you know about applying Project Management processes, tools and techniques in project.
Regular Project Management training is designed only to provide the knowledge component, enabling you to pass an exam. But exams don’t necessarily test knowledge, and passing an exam doesn’t attest to your ability to do the job. In fact, in a survey about the value of the PMI®‘s PMP® certification, the “results indicated that PMP® certification was the least valued of 15 core competencies and that there was no difference in project success rates between PMP®-certified project managers and uncertified project managers.”
Read in context at:
Starkweather, J. & Stevenson, D. H. (2011). PMP® Certification as a Core Competency: Necessary But Not Sufficient. Project Management Journal, 42(1), 31–41