1. Introduction

1.1. Network Communication

Today, few can imagine the world around us without computers, telephones and many other consumer electronic devices. These devices provide us with a wide range of functions and capabilities that make our daily activities easier, as well as helping us to work and study. Many of these functions would be useless without one important aspect: the ability to communicate and exchange data quickly.

It allows us to reach friends on the other side of the world in seconds, pay the electricity bill in seconds or buy a new pair of trainers without leaving the house. Of course, we are not going to go into all the benefits of internet access here, as that is not the main subject of the course, but we hope you will realise that everything you can do with your computer or smartphone has one thing in common. That common denominator is the computer network that was created decades ago and is the foundation of today's Internet.

What is the internet today? It is nothing more than a computer network, a very sophisticated one, with lots of connected devices, but it is still a network.