The document discusses different types of media and how technology has changed media over time. It explains that mass media like television, newspapers, and radio use technologies like satellites, cables, and printing presses that allow them to reach millions of people. However, these technologies are expensive to maintain. As a result, mass media earns money through advertising to cover costs. The document also discusses how local communities have started their own grassroots media like community radio and newspapers to cover issues important to ordinary people that may be ignored by larger media organizations.