2. Network

2.1 Introduction

A network is defined as a set of entities communicating with each other via a medium. Entities can be people (social networks), cars (road networks) or computer systems (computer networks). A distributed system consists of a set of processors linked together by a network. This network enables data to be exchanged, ensuring that the system functions correctly. These data or messages are represented in the form of packets, also known as data frames. In a packet network, each element enabling the end-to-end transport of packets is called a "node".