Internet 101

   

The Internet has become a part of our lives. We hear about it on the evening news, read about it in the papers, and see references to it in advertising. But exactly what is the Internet? And how does the World Wide Web fit into the picture?

Let's start at the beginning, with an overview of the Internet and the World Wide Web.

What is the Internet?

The Internet is a global network of computers.

Internet

A global network of computers linked together for the exchange of information. Also referred to as the 'Net .


Imagine a bunch of powerful computers, each located in different cities all over the world. These computers are connected by high-speed network connections, so they can exchange information very quickly. Figure 1.1 shows how such a network might be configured.

Figure 1.1. The Internet is a collection of computers connected by high-speed network connections.

graphics/01fig01.gif

These computers are not always directly connected to each other, so sometimes information must pass through one computer to get to another. For example, if Computer A has information that Computer F wants, the information may need to pass from Computer A through Computers B and G on its way to Computer F.

This is how the Internet works: by passing information to a computer that requests it, from a computer that has it. The information can be anything that can be stored on a computer: like an e-mail message, a Web page, a digital picture, or a computer program.

A Brief History of the Internet

The Internet has been around since the late 1960s. Back then, Cold War fears convinced the U.S. government that its defense computer systems needed protection in the event of a nuclear war. Multiple mainframe computer systems were networked together in such a way that if any one system was destroyed , information could still be shared among the others. This was called DARPAnet (short for Defense Advanced Research Projects Agency network). Later, the D for Defense was dropped, leaving ARPAnet.

In the 1980s, the military sites of ARPAnet split off, leaving behind the research sites. Additional networks ”including Usenet and BITNET, were developed and linked to ARPAnet via gateways . Internet Protocol (or IP ) was developed so that each computer on the network could route information to any other computer on the network via the shortest possible route.

Gateway

A network feature that enables information to pass between two different types of networks.


Internet Protocol (IP)

A set of instructions that enables one computer in a network to know about and exchange information with all other computers in the network.


In 1986, the National Science Foundation Network (NSFNET) was created. Based around five supercomputers, it enabled researchers to use computer resources without traveling to the computer itself. When linking computers via ARPAnet didn't work out, NSFNET built its own network, which was managed and upgraded by IBM and a number of other companies.

In 1990, NSFNET replaced ARPAnet, which was dismantled. Other smaller networks also disappeared. Companies began linking their own internal networks to NSFNET, taking advantage of its existing network connections to exchange e-mail and other information. Throughout the world, other networks were linked to NSFNET, building a global network.

In the early 1990s, the U.S. government was funding NSFNET. That stopped in 1995, when NSFNET closed down. Amazingly, the network built around it continued to function, supported by the big organizations that were linked to it ”primarily phone companies and America Online. The end result of all this is the commercial Internet we know today.

Nowadays, you don't have to be a big company to connect to the Internet. Anyone with a computer or Internet appliance can do it. The Internet is booming and access is getting cheaper, easier, and more reliable all the time. Despite the fact that the Internet isn't owned or controlled by any one individual or organization, it will continue to grow long into the future.

Internet Appliance

Any electronic device that can access the Internet. Nowadays, such functionality can be found in many cellular phones, personal digital assistants (PDAs), and televisions .


Internet Features

The Internet offers access to many features. Here are just a few that interest most Internet users:

  • E-mail. Electronic mail makes it possible to exchange written messages with other people all over the world, quickly and cost effectively.

  • Software. FTP (file transfer protocol) makes it possible to exchange computer programs or documents with others, via upload or download .

  • Discussion groups. Newsgroups and mailing lists let participants join in topical discussions with people who share their interests.

  • "Published" information. Gopher, WAIS, and World Wide Web servers make it possible to publish and retrieve information from a wide variety of sources.

Upload

To send a copy of a computer file from your computer to another computer via modem or network connection.


Download

To retrieve a copy of a computer file from another computer to your computer via modem or network connection.


It's this last feature ”published information on the World Wide Web ”that has everyone so excited about the Internet. It's the Web that makes the Internet so friendly and useful. And it's the Web that caused rapid growth of the Internet since the mid 1990s.

Internet vs. Intranet

You may have heard the term intranet so let me take a moment to explain it.

intranet

An internal network with the same features found on the Internet.


An intranet is a network that can have the same features as the Internet, but its access is limited to authorized individuals. Think of an intranet as an internal Internet. Many big companies have intranets , which they use to distribute internal information.

Here's an example. I did some Internet- related training for Colgate-Palmolive Corporation several years ago. Its intranet included legal documents, an employee directory, and forms used by the Human Resources and Facilities Management departments. Anyone with access to the intranet can access this information. But although the intranet is connected to the Internet to allow Colgate-Palmolive employees to access Internet information, firewall software prevents outsiders from accessing the intranet.

firewall

Security software that prevents outsiders from accessing the information on an intranet.


   


Putting Your Small Business on the Web. The Peachpit Guide to Webtop Publishing
Putting Your Small Business on the Web
ISBN: 0201717131
EAN: 2147483647
Year: 1999
Pages: 83
Authors: Maria Langer

flylib.com © 2008-2017.
If you may any questions please contact us: flylib@qtcs.net