What Is a Programming Language?

What Is a Programming Language?
While computer hardware has continued to evolve and improve over the last several decades, an equally important story is the development of software. Consider the following statistic. In 1981, the software industry had $140 million in sales. Three years later, sales had increased to $1.6 billion (Campbell-Kelly & Aspray, 1996, p. 260). Today, the sales of video game software and hardware alone were nearly $25 billion in 2011 (Entertainment Software Association, 2012). Computing languages—or ways that humans can tell a computer what to do—make this all possible. Since the middle of the 20th century, there have been five key generations of programming languages, as shown in Figure 3.1. Exploring these developments will enable you to better understand the present state of the software industry.