The growing sophistication of information technologies — a hallmark of the globalizing age — has had a profound and rapidly evolving effect on patterns of communications, commerce, and politics. As tiny digital microchips replaced bulky transistors and the Internet grew in scope and popularity, more and more people organized their everyday lives around the use of ever-smaller and more powerful high-tech devices.

Leisure-time pursuits were a case in point. The arrival of cable television, followed swiftly by DVDs and then online video streaming, enabled individuals to watch full-length movies or popular television shows on their personal computers or smartphones at any time and greatly diversified the options for home entertainment. Europe’s once-powerful public broadcasting systems, such as the BBC, were forced to compete with a variety of private enterprises, including Netflix, a U.S. online video provider that announced plans to expand into Europe in 2013. Music downloads and streaming audio files replaced compact discs, which themselves had replaced vinyl records and cassettes; digital cameras eliminated the need for expensive film; e-book readers, including Kindles and iPads, offered a handheld portable library; cell phone apps provided a seemingly endless variety of distractions and conveniences.

Digitalization transformed familiar forms of communication in a few short decades. Many of these changes centered on the Internet, which began its rapid expansion around the globe in the late 1980s. In the first decade of the twenty-first century, the evolution of the cell phone into the smartphone, with its multimedia telecommunications features and more functions and power than the desktop computers of the previous decade, hastened the change. The growing popularity of Internet-based communication tools such as e-mail, text messaging, Facebook, Twitter, and other social media changed the way friends, families, and businesses kept in touch. Letter writing with pen and paper became a quaint relic of the past. Skype, first introduced in 2003, offered personal computer and smartphone users video telecommunications around the world; the old-fashioned “landline,” connected to a stationary telephone, seemed ready to join the vinyl LP and the handwritten letter in the junk bin of history.

Entire industries were dramatically changed by the emergence of the Internet. With faster speeds and better online security came online shopping; people increasingly relied on the Internet to purchase goods from clothes to computers to groceries. Online file sharing of books and popular music transformed the publishing and music industries, while massive online retailers such as Amazon.com and eBay, which sell millions of goods across the globe without physical storefronts, transformed traditional distribution and retail systems.

The rapid growth of the Internet and social media raised complex questions related to personal privacy and politics. Governments and businesses can monitor personal Web use and use online tracking systems to amass an extraordinary amount of information on individuals and then use it to monitor political activities or target advertising. Privacy advocates worked with government regulators to shape laws that might preserve key elements of online privacy, and in general, rules were more stringent in Europe than the United States. Conversely, citizens could use smartphones and social media sites to organize protest campaigns. Facebook and Twitter, for example, helped mobilize demonstrators in Egypt during the Arab Spring (see page 1034) and allowed members of the Occupy movement to share news and shape strategy. A number of authoritarian states from North Korea to Iran to Cuba, recognizing the disruptive powers of the Internet, strictly limited online access.