Introduction to Internet

In this unit/module you have to complete tasks 1 to 4 and a final project. All of them are compulsory.

The unit/module is designed for three sessions of 45 minutes, the first dedicated to tasks 1 to 4 and the second and third to the final project.

To finish the unit/module you are invited to complete the final self-assessment test you can find in the tab below. 

You can access here the video How Internet works? used in Task 2.

During the video you should take notes of the new words and unknown concepts that may appear. 

After watching the video, in pairs, read carefully the transcription below. Please use Wordlink and Multidict to check the words you have not understood. It is recommended:

• Using the option From English to English to see the definition of the words instead of the translation.
• Dividing the words into two categories, General Vocabulary and Technical Vocabulary.
• Once you are sure you understand the definition, open the text editor and Copy&Paste it  to a text document in order to have it available in the next steps.

HOW INTERNET WORKS?

Let's talk about the internet. We use it all the time but do we really know how any of it works?

The internet is extremely complicated and you will need to have learned differential calculus and linear algebra…just kidding.

The Internet is an extremely simple process and to understand it simply requires you to look at it from a different perspective.

The internet is nothing…that's right it doesn't exist you may think to yourself.

Then how did I get on Youtube and watch this video?

Let me explain that in a much simpler way here we have Bob and John. They live in the same city. However they live 50

kilometers away. Bob wants to send some of this delicious pies to John except he doesn't have a car or legs so he has to have someone else deliver it for him. The mailman comes takes his product and delivers it to John. He's happy so he

sends a letter of thanks back to him.

That's in its essence how the internet works. Now let's make this into real life.

Bob is a computer and John has a computer. Now instead of roads we have wires in the ground. Bob sends a file to

John. File travels through the wire, goes to Bob and he sees that it says hi. This is called a network. When we have more than one network connected to each other it's an internetwork or internet. That is exactly how the internet works. But on a more complex level now we have a third computer. How does computer know how to send information to computer too? Obviously it needs to know what path to follow. It needs an address, we call this an IP address which stands for internet protocol.

The computers are called servers now let's spice things up a little bit. I want to access a file from Google. Well Google.com is actually just another form of the IP address. Google's IP address is actually 74 only 120 5.224.72.  to test this go into your browser and type what you see on the screen and you will be redirected into Google's page. In fact Google owns a multitude of IP addresses, enough to own a range of addresses. When you want to Google something your server connects to Google server and Google sends the information you want back to you in the form of website. In upcoming short how do websites work will explain more on this.

Now that you know how simple data transfer works you must be thinking to yourself so why am I paying my internet service provider for?

Well as you know we don't all have wires from our house going to Google servers. If we did it would be a mess of wires

and it would be a whole lot of daily digging. When you want it to connect to a website rather we pay the service providers that have the links to the web page. That's also another reason you can't just wake up and decide I want to

have a website that's named this. If you want to learn more go to how to websites work.

Now our map is beginning to look like a real map. However what is it that turns these cables into actual usable internet for us. The router and the modem here are. The router connects to the modem and it turns that so-called cable internet into Wi-Fi. We use that to transmit data back to the router which connects to the modem once again and continues on and on.

Now if we had two devices on the same network, how would the router know what information comes and goes from what? Well once again that is through the IP address which is packaged with every piece of data you send.

Now let's make a final diagram to represent the transfer. Well, actually there's one thing we're forgetting. How do things actually get sent over? If you remember from our video and how the computers work, we explained that all information in computers is broken simply down into ones and zeros. So when we send our information it all has to be broken down. When we send a picture it's broken down into small parts called packages. These packages are sent over the Internet and reassembled on the other server receiving them. Each package has a set of instructions on how to recreate it and where it's from then depending on the file format use, the file is rebuilt.

Now that we have a solidified understanding we can connect some terminology when you use a device on the Internet is a point of presence or a pop and the Internet service provider is a nap or a network access provider who allows you to get on to the internet.

Let's draw our final picture. First we have several devices on the same network, here is John and here is Bob. John wants to put a picture on Facebook so John uploads from his pop to the nap where the information travels toFacebook's pop, where the image is reassembled and stored. Now Bob is in the same house and he wants to see what John is doing upstairs. He uses his pop to connect to the nap which connects to one of Google's pops and find his facebook profile. Then that pop redirects him back to the nap toward Facebook swap, where the image is broken into packages

and sent back to John, where is reassembled and he sees it. This is a simple interaction that occurs in the Internet every time you use it, a large amount of processes are happening in a split second. So sometimes you can understand when you have slow internet.

There are many advances in the internet infrastructure and with the new fiber optics being brought in speeds are only

getting faster and faster. International networks provide their own problems with creating underground networks throughout the sea.

We hope you enjoyed this video, don't forget to comment and leave any suggestions you have and subscribe to our channel.

Thanks for watching.