The notion of computer networks remains a real mystery for many people, unless they have some knowledge of computers. However, today, everyone uses these networks in one way or another, both for work and leisure.
Do you want to learn more about the subject or deepen your knowledge in the field? Take stock of the situation thanks to this file which will explain the main points about computer networks.
What is a network?
A network is referred to when two or more entities within a group enter into communication. To do so, they must speak the same language. But the network is not only used to communicate. It also allows the sharing of information. The same is true for a computer network. It allows to put in relation several entities speaking the same computer language. It’s a “protocol”.
This network will allow to exchange information at a distance, to discuss with other people, to send data, to play online, etc. To summarize, a computer network is a group of computer entities that communicate with each other.
What is the purpose of a network?
The network allows a number of operations to be carried out, such as the sharing of data between different users, the sharing of physical resources such as printers, the use of certain applications without having to install them on one’s own computer, the search for information thanks to the Internet, communication between remote people, etc.
We can thus set up a computer network from different computers (regardless of the brand), peripherals such as printers, cables, a network card, connectors to link the networks together. Note that each type of network requires the use of special hardware.
Operating systems, drivers, application software, administration software and server software are all part of the programs that are generally found on the computers in a network.
Types of networks
Public or private networksThere are currently different types of networks, distinguished by their size, their data transfer speed and also by the maximum distance separating the most distant points on the network.
- The PAN or Personal Area Network connects different personal equipment belonging to the same user over a few meters.
- The LAN or Local Area Network is the type of network generally found in companies. It connects the machines and all the devices used by the company.
- The MAN or Metropolitan Area Network connects computers that are located in the same geographical area. It groups together several local networks.
- The WAN or Wide Area Network consists of a collection of LANs and WANs, and can thus extend to a whole country and internationally.
- The SAN or Storage Area Network is a high performance network, which is mainly intended for data transfer between servers and resources dedicated to storage.
- Private and public networks
- When it comes to computer networks, we can also distinguish between private and public networks. The difference is in the confidentiality of the data.
Private networks
In the case of a private network, all the data that passes through the network and all the resources used are strictly reserved for the private sphere, as in a home or a company. The machines do not necessarily need the Internet to communicate with each other. Here again, we can distinguish between a home network and a company network.
A home LAN does not allow you to organize the computers on the network into a corporate domain, but only into workgroups. However, this is possible on a company network.
Private networks also include VPNs or Virtual Private Networks, which allow different remote local networks to be connected using a protected tunnel that crosses the Internet. These networks must belong to the same legal entity. There are three types of VPNs: access VPNs, intranet VPNs and extranet VPNs.
Ethernet is the most widely used network today. It is a protocol that allows all computers and machines on a local network to be connected via WiFi (wireless Ethernet) or wired Ethernet. Once external users can access a network, it is referred to as a public network.
Public networks
On a public network, everyone can easily access its various resources. An example is the Internet. This network connects all the networks around the world. It is simply the largest network in existence. The Internet brings together many online services, such as the Web, data transfer, e-mail, chat or videoconferencing systems, etc.
Peer to peer or Client/Server network
There are two main types of network architecture: peer-to-peer networks and networks organized around servers (client/server).
- On a client/server network, the client machines (i.e., those that belong to the network) use the services of a server. These are programs that provide various data such as files, a connection, etc. The Client/Server network guarantees greater security and allows all data that passes through the network to be saved in a central location. However, it requires the use of expensive software and hardware. In addition, if the server goes down, it will be impossible for network users to access their data.
- In a peer-to-peer network, there is no need for a dedicated server. All machines act as both server and client. Each computer can thus freely share its resources. This type of network is less secure than a Client/Server network. However, it does not require the services of a dedicated network administrator.
