Answer:
Mass media denotes a section of the media specifically designed to reach a very large audience such as the population of a nation state. The term was coined in the 1920s with the advent of nationwide radio networks, mass-circulation newspapers and magazines. However, some forms of mass media such as books and manuscripts had already been in use centuries. The term public media has a similar meaning: it is the sum of the public mass distributors of news and entertainment across media such as newspapers, television, radio, broadcasting, which may require union membership in some large markets such as Newspaper Guild, AFTRA, and text publishers.
Mass media includes Internet media (like blogs, message boards, podcasts, and video sharing) because individuals now have a means to exposure that is comparable in scale to that previously restricted to a select group of mass media producers. The communications audience has been viewed by some commentators as forming a mass society with special characteristics, notably atomization or lack of social connections, which render it especially susceptible to the influence of modern mass-media techniques such as advertising and propaganda. The term "MSM" or "mainstream media" has been widely used in the blogosphere in discussion of the mass media and media bias.