What is Agenda Building? Political Science Explanation

From Wikipedia: https://en.wikipedia.org/wiki/Agenda_building

Agenda building describes the ongoing process by which various groups attempt to transfer their interests to be the interests of public policymakers.Conceptualized as a political science theory by Cobb and Elder in 1971, "the agenda-building perspective...alerts us to the importance of the environing social processes in determining what occurs at the decision-making stage and what types of policy outcomes will be produced.” It focuses on the relationship between society and policy maker.

Classic democratic theory focused on the assumption that calls on “public policymakers to advance the interests of civically engaged constituents, by an autonomous press” (i.e. classic theory focuses on the policy makers and media) however, it failed to account for points at which larger society of stakeholders could define the range of alternatives available for policy making.