What does "mass media" refer to?

Mass Media refers to things that communication in general. Conductors of mass media are television, radio, internet, newspapers, magazines, etc. All of these seem to shape public opinion.
Mass media can be used in a number of ways such as government officials trying to shape public actions, officials running for office trying to demoralize their opponent, soap operas helping show moral dilemmas that face our daily life, the Enquirer running spoofs, newspapers telling people which acts are to be praised and which are terrifying. All of these help to shape public interest, morals, values, and opinion.