Hi, guys, it’s Olivia from the Blog4Today. In this lesson, we’re going to deep dive into how exactly does the internet actually works. Because here’s the thing that we use every single day, and we completely take it for granted.
So, before we start developing impressive websites and web-apps for people to access the internet. We must understand the fundamentals of how the internet actually works.
What exactly is the internet? A lot of people think of it as a cloud, something that’s hanging around in the sky. It’s super complex super tricky to understand, but actually, that’s not it at all.
The internet is really simple. All it is just a long piece of wire. And the cable connects different computers to each other. So, you might have one computer that’s in Seattle and another computer that’s in London, and they can talk to each other and transfer data through this giant wire.
Now some of these computers attached to the internet have a particular job. They have to be online 24/7, ready to serve you all of the data and the files that you are requesting. When you try to access websites and the computers that are doing that job, we would call a server. And the computers that any user would use to access the internet is called a client.
Now, you can imagine a web server as a giant library that’s open 24/7. You can go in there at any hour of the day and request, ‘I want to see Google’s home page’ or ‘I want to see the latest post on Tech Crunch.’ It would then be up to serve you with all of the files and data that you would need to be able to view whatever website it is that you requested.
Now you can imagine if there’s a library that’s big enough to house all of these websites. It’s going to be pretty hard or time-consuming to quickly locate the thing that you want out of this giant library. So, how is this problem solved on the internet? 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. These are the people 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, and if you’re in the UK, then that would be something like BT or TalkTalk.
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 (Domain Name System) server. 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 also, every single computer that’s connected to the internet has an IP address.
IP is like a postal address for your computer so that when people need to send and receive files on the internet. A unique IP address can locate each computer or any device. 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.
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 analogy for some smart programming. It’s literally the backbone of the internet.
If you had a submarinecablemap.com, you could view all of the underwater cables that power the internet. The internet is made up of these vast 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 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 to reach the United States. Once that computers receive 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.
Basically, all I have is an IP address. This condition is like as if I’m sending a letter halfway across the world and my only hope for my letter will 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 126.96.36.199, and the computer that’s located at that address is, of course, the Google server. On the server, there are all of the files I would need in order to be able to view the Google home page.
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. All of that happens in a matter of milliseconds. And just to imagine the journey that my data has gone on traveling through the world thousands of times per day.
So, why don’t you give it a go? Open up your browser and type in 188.8.131.52 and hit enter to see the Google home page is served up to you through the internet.
In the next lesson we’ll learn, How Does Websites Work? Thanks today!
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