The practice and study of communication includes a wide variety of industries, from education and research, to public relations, advertising, publishing, and digital media. Many people in television, film, and radio broadcasting have academic degrees in communications, with specializations in their fields. As described by Marist College on its Web site, “Communication is a discipline that involves the study of symbolic behavior in many contexts. Regardless of their specialties, communicators are involved in fundamentally similar activities. They gather and process information, and create and disseminate messages. Advertisers, journalists, public relations practitioners, public speakers, television, radio, film, or multimedia producers, and all who communicate with others engage in these essential operations.”

The communications industry is a multibillion-dollar business. The different industries that fall under the communications umbrella, as reported by the market research group IBISWorld, include public relations, advertising, publishing, and social networking sites. The public relations industry generates approximately $16 billion in revenue. As of December 2018, there were more than 44,700 public relations businesses in operation in the United States. The growth of social networking services and mobile devices will contribute to the PR industry’s continued growth in the next few years. The advertising industry is a $54 billion business, with more than 71,500 advertising firms in the United States. The ad business has seen steady growth the past few years and that growth is expected to continue, thanks to the rise of digital mediums such as smartphones and tablets.

The publishing industry includes newspapers, magazines and periodicals, and books. Print publishing has been declining this past decade due to the increased popularity of Web-based content. IBISWorld reported the newspaper publishing industry generates $25 billion in revenue, reflectin...