Social media refers to user-created content (audio, text, video, multimedia) that is published and shared online. It is also the online technology that allows users to share content and communicate with one another. Social media has changed how we live our lives and affected how nearly every industry does business. People use social media to stay informed, compare and buy products, and keep in touch with family and friends. Companies also use social media to reach customers. They have in-house social media departments or hire consulting firms to help them develop a social media strategy, market their products, and manage their profile across various types of social media. Nonprofits and government agencies use them to spread information about their programs and services.

In a general sense, social media has been around since the beginning of the Internet, but Six Degrees, the first social-networking site, launched in 1997. Marketing professors Andreas Kaplan and Michael Haenlein identify six different types of social media. In their Business Horizons article, “Users of the World, Unite! The Challenges and Opportunities of Social Media,” they named the following:

• collaborative projects (e.g., Wikipedia)
• blogs and microblogs (e.g., Twitter)
• content communities (e.g., YouTube, Flickr)
• social-networking sites (e.g., Facebook, LinkedIn, Instagram)
• virtual game worlds (e.g., World of Warcraft)
• virtual social worlds (e.g., Second Life)

No discussion of social media is complete without mention of the Internet—the delivery method for all those blog posts, pictures, videos, and Tweets. The Internet is a worldwide network of computer networks linked through high-speed, high-volume telephone lines and cables, as well as via Wi-Fi connections. It has come a long way from its start in the 1960s as a vast, indestructible U.S. military computer network that could communicate...