Devices on a network use a set of rules, called communication protocols, to govern how data is transmitted and exchanged. The data is broken into smaller parts called packets, which are then addressed and sent to the correct destination. This process relies on various components:
- Hardware: Physical equipment like routers, switches, and cables that enable communication.
- Software: Programs that manage, monitor, and optimize network operations, such as a Network Operating System (NOS).
- Protocols: The rules that ensure consistent, accurate, and secure data transmission, such as TCP/IP, HTTP, and HTTPS.
Networks are typically categorized by the geographic area they cover.
- Local Area Network (LAN): Connects devices within a small, contained area, like a home, office, or school.
- Wireless LAN (WLAN): Functions like a LAN but uses wireless radio waves (Wi-Fi) to connect devices.
- Wide Area Network (WAN): Spans large geographic areas, like a country or continent, by linking multiple LANs. The internet is the largest example of a WAN.
- Personal Area Network (PAN): Connects devices within a very short range around an individual, such as Bluetooth headphones connecting to a smartphone.
- Virtual Private Network (VPN): Creates a secure, encrypted connection over a public network, allowing remote users to safely access a private network.
Network security is a field of cybersecurity that focuses on protecting a network's integrity, confidentiality, and availability from cyberattacks and threats. Important security measures include:
- Firewalls: Act as a barrier to filter incoming and outgoing network traffic.
- Access control: Authenticates and authorizes users to determine who can access network resources.
- Encryption: Scrambles data to prevent unauthorized access.
- VPNs: Encrypt connections to secure remote access.
- Attending events: Joining industry conferences, workshops, and meetups is a great way to meet and build rapport with peers.
- Online platforms: Professional networking sites like LinkedIn are designed to connect you with other professionals in your industry.
- Informational interviews: Arranging one-on-one conversations with people in your target field can provide valuable information and expand your contacts.
What is a computer network?
A computer network is any system that connects two or more computers or devices to share data, resources, and services. These connections can be established through physical cables, like fiber optics, or wirelessly via radio signals. Networks vary in type and scale, from small local area networks (LANs) to expansive wide area networks (WANs).
At the heart of any network is its ability to enable resource sharing and support communication and collaboration across devices. By connecting multiple endpoints, a network allows users to send and receive information quickly and efficiently. Whether you're accessing a file on a remote server, sending an email, or streaming a video, networks underpin the seamless flow of data.
The concept of computer networking dates back to the late 1960s with the development of ARPANET, the first operational computer network. Funded by the U.S. Department of Defense, ARPANET was designed to let research institutions exchange information quickly and reliably. It laid the foundation for today’s internet — the largest and most complex computer network in existence.
What are the components of a networking system?
A computer network relies on several key components to function smoothly. From the routers, switches, and servers that direct traffic, to the protocols such as TCP/IP, HTTPS, and WEP or WPA that help data move securely and efficiently, each part plays its role in allowing data to move between connected devices.
Network devices
Network devices form the backbone of any computer network: the hardware that connects, directs, and manages the flow of data. Known collectively as “nodes,” they form the infrastructure that keeps digital communication running smoothly.
Routers direct data between networks. Often confused with modems, which connect local networks to the internet, routers manage traffic within your local network and distribute internet access to multiple devices.
Servers store, manage, and distribute data or services across a network. They respond to requests from client devices, delivering web pages, email, applications, and more.
Switches link local devices, like computers and printers, and ensure that data is sent only to the intended recipient. Unlike basic hubs, which broadcast data to all connected devices, switches intelligently manage traffic, improving speed and efficiency.
Gateways act as bridges between different networks or protocols. When systems using different formats need to communicate, gateways "translate" the data so everything works together seamlessly.
Wired and wireless links
Links are the connections that enable devices in a network to communicate and exchange data. Whereas logical links represent the path that data takes across the network, and are managed by software and protocols, physical links refer to the actual wired and wireless pathways that connect devices.
The three most common types of physical links are:
Wired links, such as Ethernet cables, use physical connections to transfer data between devices. They’re often favored for their stability, lower latency, and consistent speed — ideal for high-demand environments like offices or gaming setups.
Wireless links rely on radio waves, like those used in Wi-Fi networks. They allow devices to connect without the constraints of physical cabling, offering greater flexibility and mobility, which is useful in homes, workplaces, and public spaces.
Optical links use fiber-optic cables to transmit data as pulses of light. These are the fastest and most bandwidth-rich connections available, capable of handling massive amounts of data over long distances with minimal loss.
Understanding the type of link your device uses — and how it's configured — can make a big difference in performance. If your network feels sluggish, explore practical tips on how to speed up your internet connection or dig into the reasons why your phone’s internet is so slow.
Network protocols
Just as people rely on shared languages to communicate, devices in a network depend on protocols — established rules that govern how data is formatted, transmitted, and received. These protocols ensure that communication between devices is consistent, accurate, and secure, regardless of the underlying hardware or software.
At the heart of most networking systems is the model, which organizes communication into four conceptual layers:
Network access layer: Handles the physical transmission of data over media such as cables, fiber optics, or wireless signals.
Internet layer: Breaks data into packets and ensures it reaches the correct destination, even across multiple networks.
Transport layer: Establishes a reliable connection between devices and ensures that data arrives intact and in order.
Application layer: Interfaces with software applications (e.g., web browsers, email clients) that generate and consume network data.
The TCP/IP model is a streamlined, practical counterpart to the more detailed Open Systems Interconnection model (OSI), which divides networking into seven layers. While OSI is often used for teaching and conceptual clarity, TCP/IP is what powers most real-world communications today.
Other common protocols include User Datagram Protocol (UDP), which supports fast, connectionless data transfers; IEEE 802, a family of standards for local (LAN) and metropolitan (MAN) networks; Ethernet, which governs wired network connections; Wi-Fi (wireless LAN) the protocol for wireless local area networking; and cellular standards, which define how mobile networks operate and communicate across devices.