End of Chapter Summary

Mechanical computing devices date back hundreds of years, but the first real computers were developed during the 1940s. Computers have evolved at an incredible pace since those early years, becoming consistently smaller, faster, more efficient, more reliable, and less expensive. At the same time, people have devised all kinds of interesting and useful ways to put computers to use in work and play.

Computers today come in all shapes and sizes, with specific types being well suited for particular jobs. Mainframe computers and supercomputers provide more power and speed than smaller desktop machines, but they are expensive to purchase and operate. Timesharing makes it possible for many users to work simultaneously at terminals connected to these large computers. At the other end of the spectrum, personal computers and handheld devices provide computing power for those of us who don’t need a mainframe’s capabilities. Microprocessors aren’t just used in general-purpose computers; they’re embedded in appliances, automobiles, and a rapidly growing list of other products.

Connecting to a network enhances the value and power of a computer; it can share resources with other computers and facilitate electronic communication with other computer users. Some networks are local to a particular building or business; others connect users at remote geographic locations. The Internet is a collection of networks that connects the computers of businesses, public institutions, and individuals around the globe. Email provides hundreds of millions of people with near-instant worldwide communication capabilities. With Web browsing software, those same Internet users have access to billions of Web pages on the World Wide Web. The Web is a distributed network of interlinked multimedia documents. Although it started as a tool for scientists, researchers, and scholars, the Web has quickly become a vital center for entertainment and commerce. In the last few years there’s been a trend toward Web 2.0 sites—sites created by their users—social networks, media sharing sites, blogs, and more.

Computers and information technology have changed the world rapidly and irreversibly. Our civilization is in a transition from an industrial economy to an information economy, and this paradigm shift is having an impact on the way we live and work. Computers and information technology are central to our information age, and we can easily list dozens of ways in which computers now make our lives easier and more productive. PC and Web applications, from word processing and email to multimedia and database applications, have become essential tools for people everywhere. Emerging technologies, such as artificial intelligence, offer promise for future applications. Devices that were the stuff of science fiction novels 50 years ago are appearing on store shelves. At the same time, computers threaten our privacy, our security, and perhaps our way of life. As we rush into the information age, our future depends on computers and on our ability to understand and use them in productive, positive ways.