What is the Internet? Evolved from government military research that began in the late 1960s, the Internet has grown into a worldwide network of 1.5 million computers connected by fiber-optic telecommunications lines.
How many people use it? Perhaps 20 million people, four times as many as two years ago.
What can people use it for? To send electronic mail to other users, to participate in group discussions on special-interest ``newsgroups,'' to retrieve information posted by libraries, universities, businesses, and governments.
How much does it cost? Usage may seem free (at some libraries or universities, for example) but generally costs somebody something. Companies provide connections to Internet computers (via local telephone calls) at monthly fees of $13 to $20 or more, depending on services used. Users need access to a computer with a modem.
What about other on-line services? Privately run networks such as America Online and CompuServe have about 6 million users. Atop monthly fees of around $9, these services typically charge per hour of use. Like the Internet, users can send and receive electronic mail (including messages to and from Internet users), hold bulletin board discussions, and retrieve information. The Internet, bigger and more free-form than any of these services, is more complex to navigate but offers rich possibilities.