ra-media refers collectively to all media technologies, including the Internet, television, newspapers, and radio, which are used for mass communications, and to the organizations which control these technologies.

Since the 1950s, in the countries that have reached a high level of industrialization, the mass media of cinema, radio and TV have a key role in political power. Mass media play a significant role in shaping public perceptions on a variety of important issues, both through the information that is dispensed through them, and through the interpretations they place upon this information. The also play a large role in shaping modern culture, by selecting and portraying a particular set of beliefs, values, and traditions (an entire way of life), as reality. That is, by portraying a certain interpretation of reality, they shape reality to be more in line with that interpretation.

Contemporary research demonstrates an increasing level of concentration of media ownership, with many media industries already highly concentrated and dominated by a very small number of firms.