How does the internet work?
This thing we use everyday and take it for granted.
People tend to think of the internet as a cloud, super complex, hanging in the sky.
The internet all it is is a long piece of wire, and the wire connects different computers to each other. A different computer in London, another in Seattle. Some of these computers attached to the internet have a special job, they have to be online 24/7 ready to serve you all of the data and files that you are requesting when you are trying to access website. We call this computers a server, and the computer trying to access this data a client.
Now you can imagine if there's a library that's big enough to house all of these websites. then it's
going to be pretty difficult to quickly locate the thing that you want out of this giant library,
right?
So how is this problem solved on the Internet?
Well, let's say that you're sitting at home on your computer and you type in google.com because you want to head over to the main Google home page.
What happens behind the scenes is that your browser will send a message to your Internet service provider. So these are the people who you pay to be able to access the Internet.
And if you're in the US, that's a company like AT&T or Comcast.
Now the message that you're sending the ISP is "I want to see google.com". And the ISP will then relay that message to something called a DNS server - a domain name system server. And a DNS server is essentially just a souped up phone book.
And what happens when you make that request through your browser is the DNS server will look up in its database as to what is the exact IP address of that website that you're trying to access. And every single computer that's connected to the internet has an IP address.
This is like a postal address for your computer. So that when people need to send and receive files on the Internet, each computer can be located by a unique IP address.
And once that DNS server finds the IP address, it sends that back to your browser.
So now you know the exact address where you can find the Google home page.
So, the next thing that happens, is you will send a direct request to that address through your Internet service provider.
And this message will be delivered via what's called the Internet backbone.
Now, the Internet backbone isn't some sort of analogy for some clever programming.
It's literally the backbone of the Internet.
And if you had a submarinecablemap.com, you can view all of the underwater cables that power the Internet. And the Internet is made up of these huge sprawling masses of wires, connecting all of the world's Internet users. As you can imagine it's a pretty complex world out there.
Now, if I'm sitting in London and I want to see a website that's hosted in the United States, then my browser would have to make a request that goes through one of these cables under the Atlantic Ocean in order to reach the United States.
And once that computer receives my request, they'll send back all of the relevant data. Again, through these giant cables. And to navigate all of this crazy underwater and above water wires, all I have is an IP address.
It's like as if I'm sending a letter halfway across the world and my only hope for my letter to reach my friend is that postal address on the front of the envelope.
So, once I've gotten the IP address of the website that I want to access, then my browser sends another message through the Internet service provider via the Internet backbone to the server that is located at that address 216.58.210.46. And the computer that's located at that address is of course the Google server. And on this server, there's all of the files I would need in order to be able to view the Google home page.
So, the server then sends all of those files back to me through the Internet backbone and I get to see the Google home page in my browser. And all of that happens in a matter of milliseconds.
And just to imagine the journey that my data has gone on, travelling through the world thousands of times per day.
So, why don't you give it a go?
Open up your browser and type in 216.58.210.46 and hit enter to see the Google home page being served up to you being served up to you through the Internet.