This section provides an overview of the key actors involved in public participation processes. It discusses how public participation is initiated by a variety of actors from public institutions to private organizations. The ultimate purpose of public participation is also debated, with common goals including developing citizen capacity, integrating citizens in governance, and building consensus. The main actors described are private firms/freelancers, not-for-profit organizations, elected officials, civil servants, independent public agencies, academics/researchers, project promoters, and citizens themselves. Understanding these diverse actors is important for examining the professionalization of the public participation field.