The Internet is all the computers in the world which are connected together, under the TCP/IP protocol. If your computer is connected to the Internet, that means that it is now a part of that network.

Your computer is connected to a local server. A "server" is kind of like a "boss" computer, which controls a network. It could be a small network, like yours, or a much larger network. You have probably heard people say, "the servers were down," or something like that. The servers connect many computers together, so if a server goes down, it causes a wide outage.

Your local server is connected to other, larger servers via the telephone network or possibly other networks. Those servers might be connected to national servers, which are connected to servers in other countries. Those servers are connected to smaller servers, which connect to other people's computers in countries all over the world.

In short, there is a large web of connections between computers and servers all across the world, which makes it possible for your computer to contact almost any other computer in the world. This is the Internet. The web-like structure was the source of the word "World Wide Web."

Look at this Map of the Internet below:

In this map, the end of every small thread is a server. Each junction of lines is also a server. Each server can have dozens or hundreds of computers connected to it. You get the idea of how big things are: there are a lot of computers linked together.

The important thing to remember, however, is that it is just a network--it is a lot of computers connected together. It may be impressive because of its size, but what makes the Internet work is protocols.

Protocols: Tubes Within Tubes

There are many services on the Internet, each defined by a protocol. To give a few examples:

• Most people use the Internet for browsing on web sites. Your browser uses the HTTP protocol for doing this.
• Another common use is email. Your email program uses the POP3 protocol, or possibly the IMAP protocol, to collect email, and the SMTP protocol to send email.
• You might open Skype and start a text chat, voice conversation, or video call; you are using a special protocol used just by Skype to communicate.
• If you share files (legally, one hopes!), you might be using the Gnutella or BitTorrent protocols.
• If you create a web site, you may use a special program to upload files to your web host. That program would use the FTP protocol.

There are dozens of protocols, in many different layers. The layers shown above are from the 7th, or the "Application" layer. (Don't worry, protocol layers will not be on the test.)

A protocol is important because it is how all computers agree to communicate (remember, a protocol is a set of rules and language that everyone agrees to use). When a new service becomes available on the Internet, it might use a new protocol.

Each computer has the basic protocols built-in, and you can add more protocols by downloading software and installing it. For example, if you download Skype and install it, you have added another protocol to your computer.

While the physical network of computers forms the main "Tube" of the Internet, the protocols are like smaller tubes (or wires) inside that main tube. The protocols are the real "Internet," in that they make all of your activities possible.

Think of the Internet as a pipe or 'tube' (as Senator Stevens said). It might look like this:

If the Internet is a tube, then your computer is one slice of this "tube." Your computer has all the protocols of the Internet--web, email, chat, etc.--and when you add all the computers together, they make up the whole Internet "tube."

I think of this as the "Internet Salami" metaphor.

Geography of the Internet

IP Addresses

When you surf the Internet, your computer uses protocols to connect to other computers so you can perform some activity. In reality, your computer contacts these other computers by using IP Addresses. If you recall from a previous chapter, an IP address is a four-number code assigned to a server. Each of the four numbers is "8-bit," or between 0 and 255. Here's an example:

Because the above address (converted into base-10 numbers above) has 4 groups of 8 binary digits, we call it a 32-bit address. That many digits allows for over 4 billion separate addresses. However, these addresses have been given out inefficiently. Some institutions with only hundreds or thousands of computers have been given millions of addresses; most are wasted, and never used. As a result, we are actually running out of addresses!

To fix this problem, a new IP address system, called "IPv6" (Internet Protocol version 6) has been created. Using 128 bits, it has space for 340,000,000,000,000,000,000,000,000,000,000,000,000 addresses, or 340 undecillion (yes, that's a real word). So, we should have enough of these addresses for a while. With the new IPv6 addresses, you will not see the old 0-255 number system, though; IPv6 addresses are shown in base-16, or "hexadecimal," and look like this:

2001:0db8:85a3:08d3:1319:8a2e:0370:7334

Domains

These IP addresses, however, are too difficult to remember. Seriously, could you imagine someone saying, "Check out my web site at 2001:0db8:85a3:08d3:1319:8a2e:0370:7334!" Me neither.

As a result, we needed a better way to express an address on the Internet. What was created is called the Domain Name. You know these--it's domain.com. That's a domain name, like cnn.com, wikipedia.org, or lcjapan.com.

Each domain name is connected to an IP address. In a way, they are the same thing; you can type an IP address directly into a browser. Go ahead, try this address: http://119.245.180.222. That will take you to LCJ's home page. Another way to get to the exact same page is to go to http://www.japan.lakeland.edu. So:

japan.lakeland.edu = 119.245.180.222

Think of it in the same way as you think about a phone number. If you want to call somebody, you punch in their telephone number. However, if your cell phone is smart enough, you would simply look up their name, and the phone would automatically find the right number and connect you.

That's what browsers do: when you type in a domain name, they look up the IP address for that domain name and they take you to it.

Domain names do not include "www". The "www" is simply a prefix meaning "this is on the World Wide Web." You can also see domains with "ftp," "pop," or other protocol types in front of them:

Domains also have suffixes. Suffixes come in various types, but the main ones are .com, .net, and .org for private web sites, and .gov, .edu, and .mil for government, educational, and military web sites. These are just a few, however; there are many more:

There are more, and new ones are created from time to time. Suffixes proposed but not yet official: .eco (environmental organizations), .mail (for email, as a way of cutting off spam), .geo (for geographical locations), and others.

And a Domain Is... ?

Essentially, a domain is a location on the Internet. More specifically, it is a folder on a computer. When you visit a "web site," for example, that's nothing more than a folder on a computer somewhere, which has been given the IP Address you connect to. LCJ's web site, for example, is a folder on a computer in Tokyo which has been assigned the IP Address "119.245.180.222."

A domain may have several areas. Of the different areas, two stand out: the web site and email. Therefore, the folder with a domain inside will have folders for these services. Here's the folder containing blogd.com:

The folder titled "mail" has all of my email accounts at blogd.com. The folder titled "public_html" is the one with the web site. The "logs" folder keeps a record of all activity in the domain, and the "public_ftp" folder is used for file transfers.

So you can see that there is no magical world or unknowable technological maze which contains domains and web sites; it's very simply a folder on a computer. That's all. In fact, most of what you see on web pages is just as simple: they are text files with images, and maybe other media files. The text files are the web pages. That's it.

The Master of Your Domain

You could have a domain on your own computer at home if you want; some people do this. However, it is not practical. First, you need to have a high-speed two-way connection to the Internet. Most people have a high-speed one-way connection to the Internet (downloading from it), with a slow "upload" connection. Next, your computer needs to be turned on and connected to the Internet 24/7/365. Third, you need to run a collection of special programs which allow your computer to work as a server and provide services like email routing. And if something goes wrong, you have to figure it out and fix it.

Most people don't have time or training for this, so they pay businesses to do it for them. These businesses are called "web hosts." A web host has a "server farm," or a large number of computers set up to be servers. All the computers have that high-speed two-way connection to the Internet. Each server has a large hard drive, and could contain up to a hundred or so different web sites. Technicians at the web host maintain the servers and make sure everything is running smoothly.

Minimum fees for this kind of service are around $5 to $10 a month, usually allowing the customer to keep 10 or more different domains. If you want a private server (so you don't have to share resources with other web sites), you'll be paying hundreds of dollars a month. Here's an example of a web host (it's the host for this domain, in fact).

How Do I Get a Domain?

Domain names are rented through a Domain Name Registrar. One of the most famous is GoDaddy.com. You can lay claim to a domain name there, paying around $10 a year for an ordinary domain name. Once you have claimed the domain name, it is yours as long as you keep paying for it. Most "good" domain names have already been taken, so you often have to be creative to come up with a good domain name which is still available.

After you claim your domain name at the registrar, they give you an account. Just log in, enter the special connection details that your web host gave you, and the domain name will "point" to the folder at your web host which contains your web site.

What Is a Domain Good For?

Think of the world wide web as a city. Most of us are tourists or shoppers--we just browse the web, visiting only. Some people have "property" in the city, like a home, a shop, a museum, etc. They have a place which people can go to in order to see and do things. On the Internet, this property is a domain. By typing that domain name into a browser, people can "visit" the domain, like you would visit a house or a shop.

Once you have a domain, you can put a web site into it.

Remember:

The domain is just a folder on a hard drive on a computer somewhere.

A Web Site is a folder inside the domain.

A Web Page is a plain text file in the web site.

Really, domains and web sites are nothing more than files and folders just like so many that are on any personal computer. You can (and will) create and view web pages right on your own computer.

Now You Know

Now you know, generally, what the Internet is and what web sites and web pages are. You are ready to begin learning HTML programming code.