The invention of moving pictures, the telephone, and other communications technologies between 1875 and 1900 prepared the way for a twentieth-century era of mass communications. In parallel, new information-processing technologies began with development of adding and calculating machines and culminated in the development of the first computers during the Second World War. As computing and communications technologies converged, they created the “information age.” The global availability and affordability of radios and television sets in the 1950s introduced a second communications revolution that followed the first revolution brought by telegraph and telephone. The transistor radio penetrated the most isolated hamlets of the world. Though initially less common, television use expanded into nearly every country during the 1960s and 1970s, even if there was only one television in a village.

The third, and perhaps greatest, communications revolution occurred with the first Apple personal computers in 1976, followed by the introduction of cell phones in 1985. The use of mass communications and the pace of technological development in communications have exploded since then. Cell phones allowed individuals and nations in the developing world to bypass traditional telephone lines, installation, and other obstacles, and cell phones have become among the most widely owned communications tools worldwide.

Despite the ubiquity of cell phones, the Internet, or World Wide Web, has had the greatest impact on human communication. First made available to the general public in 1994, the Internet has opened up seemingly infinite possibilities for global access to information and knowledge. Authoritarian governments have realized the threat that the Internet and social media platforms pose to their power and control. The governments of China and North Korea, for example, have spent millions of dollars trying to restrict information traveling in and out of their countries over the Internet, while the governments of the United States and other nations have spent even more to develop ways to monitor that information. Even as expanding means of communication have made censorship more difficult to enforce, they have made it even harder to keep information or communications private.

The intensity of innovation in communications and information technology created new business giants. Apple, Microsoft, Google, and IBM are entities that stand at the forefront of the contemporary world, and they absorb and distribute enormous amounts of capital. The success of these technology companies and the proliferation of computer, cellular telephone and Internet use are remarkable changes, but they also deepen a stubborn continuity: deep socioeconomic inequalities between countries and within countries. The unevenness of both the production and consumption of computer technology has resulted in a digital divide, meaning the gap in access to Internet and computer and telecommunications resources. This gap is the greatest between nations like the United States, western European countries, and Japan and nations in Africa and South or Southeast Asia. The digital divide also exists between the wealthy and poor, as well as between urban and rural areas within countries.