In the late 20th century, mass media could be classified into eight mass media industries: books, the Internet, magazines, movies, newspapers, radio, recordings, and television. The explosion of digital communication technology in the late 20th and early 21st centuries made prominent the question: what forms of media should be classified as "mass media"? For example, it is controversial whether to include cell phones, computer games (such as MMORPGs), and video games in the definition. In the 2000s, a classification called the "seven mass media" became popular.[citation needed] In order of introduction, they are:
- Print (books, pamphlets, newspapers, magazines, etc.) from the late 15th century
- Recordings (gramophone records, magnetic tapes, cassettes, cartridges, CDs, and DVDs) from the late 19th century
- Cinema from about 1900
- Radio from about 1910
- Television from about 1950
- Internet from about 1990
- Mobile phones from about 2000
