Gatekeeping is the process through which information is filtered for dissemination, whether for publication, broadcasting, the Internet, or some other mode of communication. The academic theory of gatekeeping may be found in multiple fields of study, including communication studies, journalism, political science, and sociology. Gatekeeping originally focused on the mass media with its few-to-many dynamic. Currently, the gatekeeping theory also addresses face-to-face communication and the many-to-many dynamic inherent on the Internet. Social psychologist Kurt Lewin first instituted Gatekeeping theory in 1943. Gatekeeping occurs at all levels of the media structure—from a reporter deciding which sources are presented in a headline story to editors choosing which stories are printed or covered. Including, but not limited to, media outlet owner and advertisers.

The propaganda model is a conceptual model in political economy advanced by Edward S. Herman and Noam Chomsky to explain how propaganda and systemic biases function in corporate mass media. The model seeks to explain how populations are manipulated and how consent for economic, social, and political policies, both foreign and domestic, is "manufactured" in the public mind due to this propaganda. The theory posits that the way in which corporate media is structured creates an inherent conflict of interest and therefore acts as propaganda for anti-democratic elements.