Lesson 1

An Internet Primer

The Internet is the most remarkable communication device created since the telephone. It is a vast library of information that can not be found anywhere else. But the Internet is also the "Wild, Wild West" where there are few rules and those few are often broken. As journalists, we are information specialists. It is our job to be able to go into the mouth of this beast, extract the accurate information we need and get out as fast and as efficiently as possible. The goal of this mini-course is to teach you those skills.

What is the Internet?

The Internet is a network of networks all speaking to each other in an agreed-upon language called a protocol. That protocol is known as TCP/IP. There are literally millions of networks connected to the Internet and it continues to grow at an amazing rate.

How did it get started?

In the early 1960s, the US military through the Advanced Research Projects Administration (ARPA), wanted to make sure their command structure could withstand a nuclear attack. Their system at the time relied on a central headquarters which routed all information to and from key installations or nodes. This structure was known as a hub-and-spoke network. The problem with a hub-and-spoke network was that if the hub (headquarters) was destroyed, none of the nodes could talk to each other.

ARPA funded research in the mid 60s to develop the technology needed to create a peer-to-peer network; a network that allowed every node to talk to every other node. With more than one route available, messages could bypass downed computers. For this to work, they needed a new technology that became known as packet switching.

What is packet switching and how does it work?

The Internet we know today is based on packet switching. Packet switching requires that messages sent on the Internet be broken up into bite-sized packets of information. Each packet has part of the message, it's order in the stream of packets and the address where it is coming from and going to.

Each packet is sent and finds the most efficient route through the network bypassing computers that are down. At their destination the packets are stitched back together to form the message. It's the equivalent of sending a pack of playing cards in 52 separate envelopes from Sarajevo to Banja Luka. The military saw another advantage to packet switching: it would be hard to eavesdrop on messages with this approach.

In 1969, scientists demonstrated the Internet buy sending the message "login" from UCLA to the Stanford research Insitute. Two years later, someone sketched out the Internet (something impossible to do today) and this is what it looked like.

What is the World Wide Web? Is it the same as the Internet?

The Internet should not be confused with the World Wide Web. The Internet is based on a common language or protocol (TCP/IP) based on packet switching. All computers that are part of the Internet by definition must talk this language. In turn, the Internet supports a number of other protocols on top of TCP/IP. Think of them as dialects. One of those is hypertext transfer protocol or HTTP. Computers that understand this protocol, called Web servers, are by definition, part of the WWW.

There are other protocols spoken on the Internet. Here are a the major ones.

FTP File Transfer Protocol - allows you to transfer files through the Internet
Telnet Allows you to login to another computer through the Internet
Usenet Allows you to post messages to a bulletin board called news groups
Email Allows you to send messages between users
IRC Internet relay chat -- allows you to talk real time on the Internet
http WWW - allows you to view text, graphics, sound, video through the Internet

How is the Internet organized?

With all the computers on the Internet, a method had to be devised to distinguish them from each other. In order to uniquely identify the computers on the Internet, each computer is given an IP address. Think of it as the computers phone number. It might look something like this:

216.188.155.109

But that "phone number" for the computer is too hard to remember so the designers of the Internet came up with a way to assign an easy to use unique identifier called a domain name. A domain name might look like this:

http://www.drewsullivan.com

The http you know from above. The www before the name is a convention (not a rule) that specifies your browser is requesting a Web page. You will also see sites that start with ftp meaning you are accessing an ftp site through your browser. The com extension on the end is another convention specifying that the site is a commercial site. Here are some other common domain name extensions:

.com commercial site .edu educational site
.org non-profit site .net Internet service provider
.gov governmental site .nato NATO site
.mil US military site .int International site

Each country also has their own two character extension. An example of a Web site using a country code might be http://www.bosnia.ba. Sometimes a country code is used, sometimes it is not. Here are a few of the more common ones:

.ba Bosnia-Herzegovina .yu Yugoslavia
.us United States .mk Macedonia
.de Germany .fr France
.nl Netherlands .hu Hungary

A larger list of country codes can be found here.

If you've used the web before, the Web address above should look familiar to you. It identifies which computer on the World Wide Web you have accessed. You can actually use either the domain name or the IP address to specify a Web site -- both will work. Try this for yourself. Put the IP address number in the address line of your browser and see what happens.

The full web address identifies the folder and file being requested. Let's use this Web page as an example:

http://www.drewsullivan.com/bos/lessons/lesson1.htm

This web page lesson.htm can be found:

You can also think of the Internet is as a giant warehouse filled with filing cabinets. Each filing cabinet has a unique number or name assigned to it. When you request a web page, you are specifying a cabinet, drawer, folder and page. A clerk runs to that cabinet, opens the drawer and pulls out the page you want and brings it to you.

In real life, when you type an address into your Web browser, your computer generates a request for that file and here's what happens:

In actuality, it's a little more complicated but I think you get the picture.

The Web continues to grow at a remarkable rate. The World Wide Web has been the biggest part of that growth which is remarkable because it did not exist until a few years ago. Here is an interesting Internet timeline that gives you some idea of the Internet's growth.

Here are some additional resources you might find useful if you want more information.

 

 

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