Only a peace between equals can last. Only a peace the very principle of which is equality and a common participation in a common benefit. — Woodrow Wilson, Address to the United States Senate, January 22, 1917
Participation refers to different mechanisms for individuals to express opinions – and ideally exert influence – regarding political, economic, management or other social activities. Participation can take place along any realm of human social activity, including educational, economic, political, management, cultural or familial. — Wikipedia
Participatory culture is a neologism in reference of, but opposite to a Consumer culture — in other words a culture in which private persons (the public) do not act as consumers only, but also as contributors or producers (prosumers). The term is most often applied to the production or creation of some type of published media. Recent advances in technologies (mostly personal computers and the Internet) have enabled private persons to create and publish such media, usually through the Internet. This new culture as it relates to the Internet has been described as Web 2.0. The increasing access to the Internet has come to play an integral part in the expansion of participatory culture because it increasingly enables people to work collaboratively; generate and disseminate news, ideas, and creative works; and connect with people who share similar goals and interests (see affinity groups). — Wikipedia
Here are links to pages about closely related subjects.