Mainstream media (MSM) is a term and abbreviation used to refer collectively to the various large mass news media that influence a large number of people, and both reflect and shape prevailing currents of thought. The term is used to contrast with alternative media which may contain content with more dissenting thought as they do not reflect prevailing opinion.
The term is often used for large news conglomerates, including newspapers and broadcast media, that underwent successive mergers in many countries. The concentration of media ownership has raised concerns of a homogenization of viewpoints presented to news consumers. Consequently, the term mainstream media has been widely used in conversation and the blogosphere, often in oppositional, pejorative, or dismissive senses, in the discussion of the mass media and media bias.