End of Chapter Summary

The Internet is a network of networks that connects all kinds of computers around the globe. It grew out of a military research network designed to provide reliable communication even if part of the network failed. The Internet uses standard protocols to allow Internet communication to occur. No single organization owns or controls the Internet.

You can connect to the Internet in any of several ways; these ways provide different degrees of access to Internet services. A direct connection provides the most complete and fastest service, but users can also access most Internet information through modem connections. Broadband connections approach direct connection speeds, but they aren’t universally available. Several online services have gateways to the Internet; these gateways enable users to access Internet information resources and send and receive Internet mail.

Most Internet applications are based on the client/server model. The user interface for these applications varies depending on the type of connection and the type of client software the user has. A user might type UNIX commands to a host computer or use point-and-click tools on a personal computer. Different types of servers provide different kinds of Internet services, ranging from mail to the Web.

The earliest Web pages were simple hypertext pages; today the World Wide Web contains thousands of complex, media-rich structures that offer visitors a wealth of choices. The Web uses a set of protocols to make a variety of Internet services and multimedia documents available to users through a simple point-and-click interface. Web pages are generally constructed using a language called HTML. Many Web authoring tools automate the coding of HTML pages, making it easy for nonprogrammers to write and publish their own pages. Other languages and techniques are being developed to extend the power of the Web in ways that go beyond the capabilities of HTML. Today most large, interactive Web sites are database-driven, so content can be updated automatically.

In addition to Web sites, a variety of applications are built on the protocols of the Internet and the Web. For example, people who use the Web depend on search engines to find the information they need. Search engines use a combination of automated searches and indexed databases to catalog Web resources.

Peer-to-peer computing was popularized by music sharing services, but its applications go beyond music sharing. Many businesses are exploring ways to apply P2P technology. Grid computing goes beyond P2P computing by enabling people to share processor power with others. Some organizations are working to build a grid-computing model that would make the Internet work like a shared utility.

As the Internet grows and changes, issues of privacy, security, censorship, criminal activity, universal access, and appropriate Net behavior are surfacing. Even more questions will arise when all kinds of electronic devices are attached to the Web, communicating with each other from our homes, our offices, and our vehicles. We have an important question to answer as the Internet evolves from an electronic frontier into just another part of our everyday lives: What exactly do we want our days to be like?