Citizen journalism, also known as collaborative media,: 61 participatory journalism, democratic journalism, guerrilla journalism or street journalism, is based upon public citizens "playing an active role in the process of collecting, reporting, analyzing, and disseminating news and information." Similarly, Courtney C. Radsch defines citizen journalism "as an alternative and activist form of news gathering and reporting that functions outside mainstream media institutions, often as a response to shortcomings in the professional journalistic field, that uses similar journalistic practices but is driven by different objectives and ideals and relies on alternative sources of legitimacy than traditional or mainstream journalism". Jay Rosen offers a simpler definition: "When the people formerly known as the audience employ the press tools they have in their possession to inform one another." The underlying principle of citizen journalism is that ordinary people, not professional journalists, can be the main creators and distributors or news. Citizen journalism should not be confused with: community journalism or civic journalism, both of which are practiced by professional journalists; collaborative journalism, which is the practice of professional and non-professional journalists working together; and social journalism, which denotes a digital publication with a hybrid of professional and non-professional journalism.
Citizen journalism is a specific form of both citizen media and user-generated content (UGC). By juxtaposing the term "citizen", with its attendant qualities of civic-mindedness & social responsibility, with that of "journalism", which refers to a particular profession, Courtney C. Radsch argues that this term best describes this particular form of online & digital journalism conducted by amateurs, because it underscores the link between the practice of journalism and its relation to the political and public sphere.
Citizen journalism was made more feasible by the development of various online internet platforms. New media technology, such as social networking and media-sharing websites, in addition to the increasing prevalence of cellular telephones, have made citizen journalism more accessible to people worldwide. Recent advances in new media have started to have a profound political impact. Due to the availability of technology, citizens often can report breaking news more quickly than traditional media reporters. Notable examples of citizen journalism reporting from major world events are, the 2010 Haiti earthquake, the Arab Spring, the Occupy Wall Street movement, the 2013 protests in Turkey, the Euromaidan events in Ukraine, and Syrian Civil War, the 2014 Ferguson unrest and the Black Lives Matter movement.
Being that Citizen journalism is yet to develop a conceptual framework and guiding principles, it can be heavily opinionated and subjective, making it more supplemental than primary in terms of forming public opinion. Critics of the phenomenon, including professional journalists and news organizations, claim that citizen journalism is unregulated, amateur, and haphazard in quality and coverage. Furthermore, Citizen journalists, due to their lack of professional affiliation, are thought to lack resources as well as focus on how best to serve the public.