What is a Computer Network? Definition, Types, Examples 

If you run a business, you’ll know how important a computer network is. Not only does it allow staff to share information effortlessly, but it also plays a key role in increasing flexibility, reducing costs, and making your business more efficient across the board. 

As technology has evolved, networking has too. While networking used to be a bunch of desktop computers connected by wires and cables, these days networking includes wireless systems and connections and other advanced technologies.

This article delves into the meaning of a computer network, exploring its types and benefits while giving real-life examples of computer networks in action.

What is a Computer network? Definition

A computer network is a system that connects two or more computing devices together to allow them to communicate and share resources. 

These devices include everything from a mobile phone to a server and can be connected through physical wires such as fibre topics, or entirely wirelessly via WiFi. Devices in a computer network act as network nodes, interacting with each other through a set of standardized communication protocols.

The primary purpose of a computer network is to enable communication and data exchange between different devices, allowing them to work together efficiently.

Read: What is Computer Architecture? Definition, Types, Structure

Think of it like a web of connections that lets these devices "talk" to each other. If one part of the computer network is disconnected, the rest of the network can still communicate. 

Networks come in various sizes and structures, ranging from a simple home network with your PC and printer to colossal internet backbones spanning the globe.

What was the First Computer network?

The first computer network was the ARPANET, which was Developed in the late 1960s by a branch of the US Department of Defense called the Advanced Research Projects Agency (ARPA). 

The US Department of Defense wanted a communication system resilient to attack, one that could survive even if parts of the network were destroyed. Traditional centralized systems were vulnerable, so researchers turned to a new idea: decentralization.

This ARPANET pioneered the use of packet switching, a revolutionary technology that breaks down data into smaller packets and sends them over the network independently. This ensured efficient routing and redundancy, making the network resilient to disruptions.

It also introduced the TCP/IP protocol suite, a set of communication protocols that laid the foundation for the Internet's open and interoperable architecture.

ARPANET served as a testbed for various networking technologies, including email, file transfer protocols, and early forms of online chat, and led to the development of the internet by providing the infrastructure and technical groundwork for its expansion.

What are the components of a computer network?

Computer networks are complex systems made up of several key components working together seamlessly. They’re built with two basic components – network devices and links. These links connect two or more nodes in a way that is defined by communication protocols. 

As well as these basic building blocks, several key components of computer networks are required to keep devices connected to the network. These components can be split into two categories: hardware and software. 

Hardware components

1. Nodes: These are the devices connected to the network, like computers, smartphones, printers, servers, etc. They act as endpoints for communication and resource sharing.
2. Network interface cards (NICs): These are the physical cards installed in devices that allow them to connect to the network and send/receive data. Think of them as the network ports for your devices.
3. Transmission cables/signals These are the physical or wirelesspathways through which data travels, like.
4. Networking devices: These are specialized hardware units that handle data flow and network management, including:
   • Hubs: Simple devices that broadcast data to all connected nodes, used in smaller networks.
   • Switches: Forward data only to the intended recipient, improving network efficiency.
   • Routers: Direct data packets between different networks, enabling communication across larger spans.
   • Firewalls: Security devices that filter incoming and outgoing traffic to protect the network from unauthorized access. These can be open-source firewalls or closed-source firewalls. 
   • Modems: Translate signals between digital data and analogue formats for communication over telephone lines or cable lines.

Software Components 

1. Network Operating Systems (NOS). These are specialized operating systems designed to manage and control network resources, such as user access, security, and data flow. Common NOS examples include Windows Server, Linux, and macOS Server.
2. Network Protocols: These are sets of rules that govern how devices communicate and share data on the network. They define everything from data formatting and transmission to error detection and correction. Common protocols include TCP/IP, UDP, and Ethernet.

Types of computer networks

Computer networks can be classified based on criteria, like their transmission medium, network size, topology, and organizational intent. There are many different types of computer networks, each with its purpose and size. These include:

1. Personal Area Network (PAN). A PAN is a small network that connects devices like smartphones, laptops, and wearables over a short distance, typically using Bluetooth or Wi-Fi. 
2. Local Area Network (LAN). A LAN is a network that connects devices in a limited area, such as a home, office, or school. LANs are typically used to share resources like printers, files, and internet access. 
3. Wireless Local Area Network (WLAN).  A WLAN is a LAN that uses Wi-Fi to connect devices wirelessly. WLANs are becoming increasingly popular because they are more convenient and flexible than wired LANs. 
4. Campus Area Network (CAN). A CAN is a network that connects multiple LANs together, typically on a college campus or in a large office building. CANs are often used to provide internet access and other shared resources to a large number of users. 
5. Metropolitan Area Network (MAN). A MAN is a network that covers a larger area than a LAN, such as a city or town. MANs are often used to connect businesses, government agencies, and other organizations together.
6. Wide Area Network (WAN). A WAN is a network that covers a large geographical area, such as a country or even the entire world. WANs are often used to connect businesses, government agencies, and other organizations over long distances. The internet is a WAN. 
7. Storage Area Network (SAN). A SAN is a network that is specifically designed for storing data. SANs are typically used in large data centres where there is a need to store and access large amounts of data quickly and efficiently. 
8. Virtual Private Network (VPN). A VPN is a network that creates a secure tunnel over a public network, such as the Internet. VPNs are often used by businesses to allow employees to securely access company resources from remote locations.

Examples of Computer Networks

Examples of computer networks can be found all around you, designed to serve different purposes. Some of the most common, real-life examples of computer networks include:

• Your home network. Connecting your laptop, smartphone, printer, and smart TV allows you to share files, print documents, and stream content across devices.
• Bluetooth headphones. Wirelessly connecting your phone to your headphones is a PAN example.
• School or office network. Connecting computers, printers, and servers within a building allows resource sharing and internet access for employees or students.
• Cafe with free Wi-Fi. This allows customers to connect their laptops or phones to the internet for browsing, working, or streaming.
• ATM network. Connecting ATMs across a bank's network to allow customers to access their accounts from various locations.
• Cloud Computing Network. Cloud service providers like Amazon Web Services (AWS), Microsoft Azure, and Google Cloud Platform (GCP) host a multitude of virtual servers and services.
• Smart City Network. A smart city implements smart infrastructure, such as traffic management systems, surveillance cameras, and environmental sensors connected through a network.

These are just a few examples of computer networks in action. As technology advances, the ways we connect devices and create networks will continue to evolve and shape our world.