Today we are going to cover a topic that is essential for all IT professionals: how a computer network works.
The different types of computer networks
Before diving into how a computer network works, it is important to know the different types of networks that exist. In this section, we will cover the main types of computer networks found in the professional world.
Local Area Networks (LAN)
Local Area Networks ( LANs) are computer networks that cover a small geographic area, such as an office, a building, or a group of buildings located close to each other. They allow connection and communication between computers and other electronic devices within that area.
Wide Area Networks (WAN)
Wide Area Networks ( WANs) are computer networks that cover a much larger geographic area than LANs, spanning hundreds or even thousands of kilometers. They enable connection and communication between computers and other electronic devices located over large distances.
Personal Area Networks (PAN)
Personal Area Networks ( PANs) are small computer networks, typically used to connect personal electronic devices, such as a computer, smartphone, tablet, or smartwatch.
How a computer network works
Now that we have introduced the different types of computer networks, let’s take a look at how they work. We will cover the basics to understand how data is transmitted and exchanged between different devices within a network.
The OSI model
The Open Systems Interconnection ( OSI ) model is a theoretical model that describes how data is transmitted from one device to another within a network. It is composed of seven layers, each with a specific role in the communication process.
- Physical layer: concerns the hardware aspects of the network (cables, hubs, etc.)
- Data Link Layer: Manages the transmission of data between network devices
- Network layer: Routes data between network devices using IP addresses
- Transport layer: Ensures reliable and error-free delivery of data between devices
- Session layer: Establishes, manages, and terminates connections between devices
- Presentation layer: formats data so that it can be understood by devices
- Application layer: concerns applications that use the network to communicate
Communication protocols
Communication protocols are standardized rules that define how devices should communicate with each other within a network. There are many protocols, such as TCP/IP, UDP, HTTP, FTP, etc., each with a specific role.
The building blocks of a computer network
A computer network cannot function without a set of elements that allow it to ensure connection and communication between devices. In this section, we will present the main constituent elements of a computer network.
The devices
Devices are the hardware elements that enable connection and communication between users and resources on a network. They can be computers, servers, routers, switches, wireless access points, etc.
Transmission media
Transmission media are the physical supports (cables, optical fibers, radio waves, etc.) that enable the transmission of data between network devices.
Network services
Network services are the applications and services that enable users to access resources and communicate within a network. They include messaging, file sharing, access rights management, and more.
The Importance of Computer Network Security
Network security is a major issue for businesses and individuals in a world where computer threats are increasingly present. In this section, we will discuss the main threats and the security measures to put in place to protect a computer network.
The threats
The threats to a computer network are numerous and varied: denial of service (DoS) attacks, intrusion, data theft, and malware propagation. It is essential to be aware of these threats and to implement appropriate security measures to counter them.
Security measures
Among the security measures to be implemented to protect a computer network, we find the use of firewalls, the installation of antivirus and antimalware, the implementation of strict security policies, user training, etc.
Finally, all IT professionals must understand how a computer network works. The basics presented in this article will allow you to understand the different types of networks, how they work, their constituent elements, and the importance of security. This will give you a solid foundation of knowledge to calmly and competently address the issues related to computer networks within your company.
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