The idea behind “citizen journalism” is that news can be produced by ordinary people who have never been introduced to any professional journalistic training. “Citizen media”, “participatory media”, “street journalism”, “grassroots journalism”, “open-source media”, “the people’s media”… etc are all names that may refer to citizens taking part in the process of reporting news. This presentation attempts to give you an idea about the main concepts behind “Citizen Media”, shows how this latter functions in the U.S. and how people and professional media interact in the U.S. on the basis of the traditions of “citizen media.”