Introduction

What happens when you type "https://www.google.fr" in your browser's address bar? Your computer will try to communicate with another computer probably located thousands of kilometers from your home.
To establish this communication, the 2 computers must of course be "connected". We say that our 2 computers are networked.
There are enormous numbers of networks (most of the school's computers are "networked"), some networks are connected to other networks which are themselves connected to other networks... which forms "networks of networks of networks...". Do you know what we call this multiple assembly of networks? The Internet!

The idea of connecting computer networks to other computer networks dates from the early 70s with the ARPAnet project which is, with good reason, considered the ancestor of the internet.

Here is a video that will help you understand the basic principles of the internet. We will have the opportunity during the year to revisit the concepts covered in this introductory video by going into a little detail.

Activity

As explained in the video above, in order to be able to identify itself, every computer has an address on a network: its IP address.

An IP address is of the form "74.125.133.94" (this IP address corresponds to the google server "google.fr")

IP addresses are of the form: "a.b.c.d", with a, b, c and d numbers between 0 and 255. We will have the opportunity to come back to this a little later.

N.B. Another standard is being deployed, the IPV6 standard (while the IP addresses seen above belong to the IPV4 standard). Why this new standard? Because with the IPV4 system, there is a risk, in the coming years, of running out of available IP addresses on the internet.