The Internet is millions of computers throughout the world, all connected by cables. In professional networking diagrams, the Internet is always displayed as a cloud like in Figure 1.1.6. The cloud is a good analogy because just as a cloud is made up of millions of tiny water droplets, the Internet is made up of millions of computers.
You connect to the Internet through a device called a modem, and an ISP (Internet Service Provider). Your ISP might be MSN, America Online, Comcast, Juno, or any of several hundred other companies.
Figure 1
The term online means "connected to the Internet". When your computer is online, you have access to all the stuff on the Internet, as well as all the stuff on your local hard disk. The term offline means "not connected to the Internet", sort of like snipping the wire that runs from your computer to your ISP. When you're offline, you only have access to the stuff that's on your own hard disk. You can't get to things on the Internet when you're offline.
The Internet provides many services, the most popular being e-mail and the World Wide Web (also known as the Web). The program you use to do e-mail is not Windows XP. Rather, it's some other program, known as an e-mail client. Your e-mail client might be America Online, MSN, Outlook Express, or any of a dozen or so other programs.
The program you use to access the Web is called a Web browser, and yours might be Microsoft Internet Explorer, MSN Explorer, America Online, Netscape Navigator, or something else. The page you're reading right now is a Web page, and you're viewing it with your Web browser.
