Computer Networks: Definition, Features, Components, and Types

A computer network is defined as a system that connects two or more computing devices to send and share information. Below we will discuss computer networks in detail. Very important in network monitoring, check out the complete info about computer networks below.

What is a Computer Network?

A computer network is a system that connects two or more computing devices to send and share information. Computing devices include everything from cell phones to servers. These devices are connected using physical cables such as fiber optics, but they can also be wireless.

The first working network was called ARPANET, created in the late 1960s. Researchers from the US government were sharing information at a time when computers were still large and difficult to transport. Now computers have come a long way from that basic network.

Today’s world revolves around the internet, which is a network of networks, connecting billions of devices around the world. Companies of all sizes use networks to connect their employees’ devices and shared resources such as printers.

Characteristics of Computer Networks

Computer networks have several characteristics that include security, reliability, and scalability. Here are the full characteristics:

Security

• Protects data: computer networks protect data and resources from unauthorized access, attacks, and breaches.
• Uses security protocols: security protocols such as Virtual Private Network (VPN) and Secure Sockets Layer (SSL) protect data.
• Using firewalls and encryption: firewalls and encryption mechanisms protect data.

Reliability

• Having alternative sources of supply: computer networks have multiple sources of supply to ensure reliability.
• Backing up critical resources: critical resources are backed up on multiple machines to ensure accessibility.

Scalability

• Can be upgraded to meet changing needs: computer networks can be upgraded to meet changing needs while maintaining high performance.
• Can meet more users: computer networks can handle more users without becoming congested.

Components of a Computer Network

A computer network consists of several important components, namely:

1. Network Devices

Also referred to as nodes, these are computing devices that need to be connected in a network. Some network devices include:

• Computers, cell phones, and other consumer devices: these are end devices that are accessed directly and frequently by users.
• Servers: application or storage servers where the main computing and data storage occurs. All requests for specific tasks or data go to the server.
• Router: routing is the process of selecting the network path through which data packets travel.
• Switch: repeaters are to networks what transformers are to power grids. Repeaters are electronic devices that receive network signals and clean or amplify them. A hub is a repeater with multiple ports, data is forwarded to the available ports while a bridge is a smarter hub that sends data to the destination port. A switch is a multi-port bridge.
• Gateway: a hardware device that acts as a gateway between two different networks. A gateway can be a firewall, router, or server.

2. Links

A link is a transmission medium that can consist of wired and wireless links.

• Wired links: examples of wired technologies used in networking include coaxial cables, telephone lines, and fiber optics. The one widely used today, optical fiber, carries light pressure to represent data.
• Wireless links: network connections can also be made via radio or other electromagnetic signals. Examples are communication satellites, cellular networks, and the radio spread spectrum.

3. Communication Protocol

A communication protocol is a set of rules followed by all nodes involved in information transfer. Some common protocols include the internet protocol suite (TCP/IP), IEEE 802, Ethernet, wireless LAN, and cellular standards.

TCP/IP is a conceptual model that standardizes communication in modern networks. This model suggests 4 functional layers of communication protocols, namely:

• Network access layer: how data is physically transferred.
• Internet layer: responsible for packaging data into intelligible packets and allowing it to be sent and received.
• Transport layer: allows devices to maintain a conversation by ensuring the connection is valid and stable.
• Application layer: outlines how high-level applications transfer data.

4. Network Defense

Although nodes, links, and protocols form the foundation of a network. Modern networks cannot stand alone without their defenses. Security is especially important when large amounts of data are generated, moved, and processed over the network.

Some examples of network defense tools include firewalls, intrusion detection systems (IDS), intrusion prevention systems (IPS), network access control (NAC), content filters, proxy servers, anti-DDoS devices, and load balancers.

Types of Computer Networks

Computer network types can be divided based on geographic scale and intended use. Here are the full details:

Based on Geographic Scale

• Nanoscale: a network that enables communication between very limited sensors and actuators.
• Personal Area Network (PAN): a network used by one person to connect several devices, such as a laptop to a scanner, etc.
• Local Area Network (LAN): a local network that connects devices within a limited geographic area, such as a school, hospital, or office building.
• Storage Area Network (SAN): a specialized network that facilitates block-level data storage.
• Campus Area Network (CAN): a network used only in the campus area, it is a collection of interconnected LANs. It is usually used by large entities, such as campuses or governments.
• Metropolitan Area Network (MAN): a large computer network that spans an entire city.
• Wide Area Network (WAN): covers larger areas such as cities, states, and even countries.
• Enterprise Private Network (EPN): a single network used by large companies to connect multiple office locations.
• Virtual Private Network (VPN): a private network used on top of a public network.
• Cloud: technically a WAN whose infrastructure is provided in the cloud.

Based on Purpose of Use

• Intranet: a set of networks managed and controlled by a single entity. Generally, it is the most secure type with access for authorized users only. Usually, intranets exist behind a router in a local area network.
• Internet: a collection of multiple networks connected by routers and covered by network software. This global system connects governments, researchers, companies, the public, and individual computer networks.
• Extranet: similar to an intranet, but with connections to specific external networks. In general, extranets are used for sharing resources with remote partners, customers, or employees.
• Darknet: an overlay network that runs on the internet and is only accessible by specialized software. Darknets use unique and customized communication protocols.

Since they were first invented, computer networks have undergone rapid development. To stay safe, be sure to always monitor them with Netmonk’s reliable services. Visit the Netmonk website for more info!