What is the Internet? A very reasonable question these days and yet one that is deceptively simple with a potentially complicated answer.
There is however a great analogy to be able to describe “What is the Internet?”
The Internet is 3 things working together in harmony. Network, Protocols and Applications. However to most people that could be Double Dutch.
Here is a simple analogy to put each in context. Roads, Rules of the Road and Vehicles.
N.B. I’m not going to get very detailed about everything, this article is designed to provide a high level overview for people who want to ask “What is the Internet?”
Roads
The Internet has a nickname, the Information Super Highway… yet what does that even mean.
Quite simply imagine roads that go all over the world. This is the network part of the internet. The majority of which are sub-marine cables.
You can have a look at these cables in detail here on the very imaginatively entitled website Submarine Cable Map. https://www.submarinecablemap.com/
Instead of roads you have cables. A network. Technology has moved on a bit and so these connections can also use Microwaves, Lasers and Radio Waves instead of cable.
Some of these cables use copper, but most of the long haul, high speed connections use glass in a thin cable, called fibre optic cables.
This road network is brilliant because it has redundancy. The Internet was designed to be broken and remade frequently.
One road can close and no problem the system just takes another route. Potentially going East to West instead of West to East.
In this way there is no one country, company or entity that controls the Internet. The information gets from A to B via a route that’s available.
Furthermore this ingenious approach enables new cables, routes and networks to be added seamlessly.
It even facilitates political and geographic rerouting if necessary… keeping everyone happy.
The Internet Rules of the Road
Ok, so the Interconnected Network or Internet, has roads… that should be straight forward enough… however to use a road there need to be agreed rules.
Different countries allow cars to drive on different sides of the road. When the designers were pulling the rules of the Internet together… they made the rules global so there is one hymn sheet for everyone to sing from.
These Internet rules of the road are called protocols.
The International Standards Organisation or ISO is charged with keeping them international.
All the protocols live in a single model structure with a very imaginatively titled name… the Open Systems Interconnectivity model for Information Interchange. Frequently referred to as the OSI model. (colloquially pronounced aussie model)
The rules break down different things but there are three major sets of rules that are REALLY handy.
The model is read from the bottom up.
Physical Layer
These protocols handle the 1s and 0s of the internet. Like Morse code these rules dictate how one device physically chats to another.
Network Layer
If you have roads then you naturally have addresses, the destinations at the end of the road or along the way.
An IP or Internet Protocol address is a set of numbers which identifies a piece of equipment… and address the road ends at.
DARPA (Defence Advanced Research Projects Agency) designed IP version 4 or IPv4 in the late 1970s. It caters for about 4,294,967,296 unique addresses…
No one expected IPv4 needing more addresses. Yet in 2011 we kinda ran out of addresses. We currently “share” addresses which is not always ideal.
In 1999 we got IP version 6 or IPv6.
This very much improved approach supports 2 to the power of 128 addresses… or the idea that every grain of sand in the world could have its own IP address if it wanted one.
Yep that should be enough… shouldn’t it?!
Transport Layer
The problem with moving big things from one place to another… is you generally can’t.
Instead break them up… move the pieces and reassemble them again at the far end.
The Transmission Control Protocol, or TCP, is responsible for numbering the pieces and putting them back together again at the far end.
All this stuff happens so you don’t even have to think about it.
Vehicles
Ok, so we have road, we have rules of the road… last piece of the puzzle are vehicles. In Internet parlance, we’re now looking at applications within the Application Layer of the ISO OSI model.
- The cars of the road is HTTP or Hyper Text Transfer Protocol. Along with the secure version, HTTPS, this application looks after our web surfing.
- Vans… look after emails… using SMTP or simple mail transfer protocol.
- Need to move a monster file… need a truck, then you’re going be best served using FTP or File Transfer Protocol.
That’s not to say you can’t move stuff using other protocols! Tools built for specific tasks tend to have situational advantages.
You could move all the stuff to build a house in cars, but it would take a lot more hassle than using a truck.
Keeping things simple and light hearted
The Internet is an evolving entity.
Starlink from SpaceX is building a massive extension to the physical network using satellites.
The speeds of connections evolve and increase with the advent of 4G and 5G technologies providing faster ways to link into the internet.
Thousands of people have contributed ideas, efforts, programming skills and engineering skills to bring this model together.
To fully understand the complexities and nuances of even one layer of the OSI ISO model can be a lifetime career and for this reason, techies can sometimes make the internet seem “mystical”.
It’s not… it’s a set of roads, with rules and vehicles. The more you learn about how the road system works, the better you can use it to your advantage.
The IT Crowd, a British comedy series, introduce “the Internet”. Hopefully at this stage of the article the Internet joke makes sense.
| Part 1 | Part 2 |
| https://www.youtube.com/watch?v=iDbyYGrswtg | https://www.youtube.com/watch?v=Vywf48Dhyns |
Conclusion
There you go. What is the Internet?
The Oxford English Dictionary went with “a computer network comprising or connecting a number of smaller networks, such as two or more local area networks connected by a shared communications protocol; an internetwork;”
I naturally prefer my own
“An interconnected network of devices comprising a physical network, protocols and applications.”
Bet you didn’t think that would make sense so quickly!
