Since its very earliest days, the Internet has been concerned primarily with one taskmaking it easier for people to communicate with one another using computers. The Internet was created to enable university researchers to share their thoughts, work, and resources, and for military people to communicate with each other in case of war and even, theoretically, a nuclear attack.
Today, more than two decades after the inception of the first networks that grew into the Internet, it is still primarily a communications medium. Millions of people from all over the world share their thoughts, hopes, work, gossip, and comments on the wires and computers that make up the Internet. Many of the means of communication, such as electronic mail, have changed very little in the past 20 years. Yet other, entirely new ways of communicating have been devised, such as enabling you to use the Internet as your telephone, completely cutting out long-distance charges, even if you're calling to the other side of the world. Some technologies enable people to communicate privately, one on one; others allow for vast discussion groups that span the globe; and still others enable both private communication with one person and public communication with large groups.
This section of the book looks at the main ways people communicate on the Internet.
Chapter 11, "How Email Works," takes a long look at what continues to be the most popular way for people to communicate on the Internetelectronic mail, or email. Email remains possibly the greatest use of the Internet and is used for business and personal communication. You'll see how email gets routed from your computer through the maze of wires that makes up the Internet and then ends up in the proper recipient's inbox. You'll look at all the elements of a mail message and learn how you can send binary files, such as pictures and sounds, through email. You'll also explore mailing lists, where you can subscribe to any one of thousands of public discussions via email or receive what are essentially electronic newsletters delivered to your email inbox. You'll also look at how you can look up anyone's email address using white page directories that use a technology called the Lightweight Access Directory Protocol (LADP). Finally in this chapter, you'll take a look at how email can be encrypted so that snoopers and hackers can't read it as it makes its way across the Internet.
Chapter 12, "How Email Spam Works," covers one of the most controversial modes of communication on the Internetthe use of spam, the equivalent of junk mail via emailthat is sent to millions of people each day. Although spam is a problem on newsgroups as well as email, email is the greatest area of controversy. Spam annoys people and wastes their time while they clean out their mailboxes; it clogs the Internet so that other messages might be delivered late (or not at all); and it can be delivered by piggybacking onto other people's email servers, costing them money. The chapter looks at how spam is sent, as well as ways that it can be blocked.
Chapter 13, "How Newsgroups Work," explores Usenet newsgroupspublic discussion groups in which anyone can participate. Many thousands of these groups focus on every subject conceivable. You'll see how newsgroups work and how you can decipher their often-arcane names.
Chapter 14, "How Internet Chat and Instant Messaging Work," covers the various ways people can chat on the Internet. When people chat on the Internet, they don't actually speak but type comments on their keyboards instead, and then people all over the world can read and respond to them. This chapter closely examines how instant messaging worksa way in which people can chat one on one with others. Two of the most popular pieces of software for communicating on the Internetusing America Online Instant Messenger (AIM) and ICQare chat software. This chapter also discusses the first type of Internet chat, called Internet Relay Chat (IRC). Although not as popular as it used to be, it's still a way many people chat with each other online. And it also looks at how chat rooms work, in which groups of people can communicate with each other.
Chapter 15, "How Skype and VoIP Work," details one of the more intriguing uses of the Internetusing it as your telephone. With a microphone and speakers, or a headset, you can make phone calls right from your PC as long as you have an Internet connection. In fact, you can also use the Internet to make phone calls without even using your PCjust plug a phone into your cable modem, DSL modem, or home network router, and use the phone as you would any other. There are a variety of ways to make calls using the Voice over Internet Protocol (VoIP), such as using free software called Skype. With Skype, you can make direct calls to other Skype users all over the world for free, or call regular telephones anywhere in the world for pennies a minute.
Finally, Chapter 16, "How Blogging and RSS Work," covers one of the biggest phenomena to hit the Internetblogs, also called weblogs. Blogs allow anyone to post their thoughts and insights online, and have become so popular that it has affected the outcome of a presidential campaign, and become one of the most influential technologies on the planet.
