Final answer:
Interest groups include both public sector government agencies and various private sector organizations, such as labor unions, that aim to influence public policy and support their members' collective interests.
Step-by-step explanation:
The blank in the question is referring to interest groups, which encompass a wide array of organizations that aim to influence public policy and decision-making. These include all public sector government agencies as well as a variety of private sector organizations such as labor unions, museums, and religious organizations. Interest groups cater to the collective interests of their members, lobby for favorable laws and policies, and may provide benefits like public goods to the larger community.