What is Computer Networking?

A computer network is a system that connects many independent computers to share information (data) and resources. The integration of computers and other different devices allows users to communicate more easily. A computer network is a collection of two or more computer systems that are linked together. A network connection can be established using either cable or wireless media. Hardware and software are used to connect computers and tools in any network.

What Do Computer Networks Do?

Computer Networks are one of the important aspects of Computer Science. In the early days, it is used for data transmission on telephone lines and had a very limited use, but nowadays, it is used in a variety of places.

Computer Networks help in providing better connectivity that helps nowadays. Modern computer networks have the following functionality:

• Computer Networks help in operating virtually
• Computer Networks integrate on a large scale
• Computer Networks respond very quickly in case of conditions change
• Computer Networks help in providing data security

Key Components of a Computer Network

In simple terms, a computer network is made up of two main parts: devices (called nodes) and connections (called links). The links connect the devices to each other. The rules for how these connections send information are called communication protocols. The starting and ending points of these communications are often called ports.

1. Network Devices

Basic hardware interconnecting network nodes, such as Network Interface Cards (NICs), Bridges, Hubs, Switches, and Routers, are used in all networks.

2. Links

Links are the ways information travels between devices, and they can be of two types:

• Wired: Communication done in a wired medium. Copper wire, twisted pair, or fiber optic cables are all options. A wired network employs wires to link devices to the Internet or another network, such as laptops or desktop PCs.
• Wireless: Wireless means without wire, media that is made up of electromagnetic waves (EM Waves) or infrared waves. Antennas or sensors will be present on all wireless devices. For data or voice communication, a wireless network uses radio frequency waves rather than wires.

3. Communication Protocols

A communication protocol is a set of rules that all devices follow when they share information. Some common protocols are TCP/IP, IEEE 802, Ethernet, wireless LAN, and cellular standards. TCP/IP is a model that organizes how communication works in modern networks. It has four functional layers for these communication links:

• Network Access Layer: This layer controls how data is physically transferred, including how hardware sends data through wires or fibers.
• Internet Layer: This layer packages data into understandable packets and ensures it can be sent and received.
• Transport Layer: This layer keeps the communication between devices steady and reliable.
• Application Layer: This layer allows high-level applications to access the network to start data transfer.

Most of the modern internet structure is based on the TCP/IP model, although the similar seven-layer OSI model still has a strong influence.

IEEE 802 is a group of standards for local area networks (LAN) and metropolitan area networks (MAN). The most well-known member of the IEEE 802 family is wireless LAN, commonly known as WLAN or Wi-Fi.

4. Network Defense

While nodes, links, and protocols are the building blocks of a network, a modern network also needs strong defenses. Security is crucial because huge amounts of data are constantly being created, moved, and processed. Some examples of network defense tools are firewalls, intrusion detection systems (IDS), intrusion prevention systems (IPS), network access control (NAC), content filters, proxy servers, anti-DDoS devices, and load balancers.

How Does a Computer Network Work?

Computer Networks simply work using nodes and links. Data communication equipment is simply termed as Nodes. For example, Modems, Hubs, Switches, etc. whereas links in Computer networks can be referred to as a connection between two nodes. We have several types of links like cable wires, optical fibers, etc. 

Whenever a Computer Network is working, nodes have the work of sending and receiving data via the links. Computer Network provides some set of protocols that help in following the rules and protocols.

Criteria of a Good Network

• Performance: It can be measured in many ways, including transmit time and response time. Transit time is the amount of time required for a message to travel from one device to another. Response time is the elapsed time between an inquiry and a response. The performance of the network depends on a number of factors, including the number of users, the type of medium & Hardware.
• Reliability: In addition to accuracy is measured by frequency of failure, the time it takes a link to recover from failure, and the network's robustness in catastrophe. 
• Security: Network security issues include protecting data from unauthorized access, protecting data from damage and development, and implementing policies and procedures for recovery from breaches and data loss.  

Types of Computer Network Architecture

Computer Network Architecture is of two types. These types are mentioned below.

• Client-Server Architecture: Client-Server Architecture is basically the architecture where the clients and the server are connected as two clients can communicate with each other and the devices present work as servers in the network.
• Peer-to-Peer Architecture: Peer-to-Peer Architecture, computers are connected to each other and each computer is equally capable of working as there is no central server here. Each device present here can be used as a client or server.

Key Objectives of Creating and Deploying a Computer Network

No industry—whether it's education, retail, finance, tech, government, or healthcare—can function without well-designed computer networks. The larger the organization, the more complex the network becomes. Before starting the challenging job of creating and setting up a computer network, here are some key objectives to consider.

• Resource Sharing - Networks allow data and hardware to be shared across departments, locations, and time zones. This supports interdepartmental work—for example, marketing can use customer and product data to guide top-level decisions.
• Resource Availability & Reliability - Resources can be accessed from multiple locations, with backups across machines ensuring reliability even during hardware failures.
• Performance Management - As companies grow, networks can boost performance by adding processors and storing data in optimized databases, making retrieval faster and smoother.
• Cost Savings - Instead of costly mainframes, networks allow strategic processor additions. Centralized access reduces operational time, IT support needs, and overall costs.
• Increased Storage Capacity - Network storage is ideal for data-heavy teams like data science. Centralized repositories efficiently handle growing data needs without requiring individual setups.
• Collaboration & Communication - Networks enhance collaboration through shared files, synced calendars, and tools like Slack. Emails remain the formal mode of communication with external parties.
• Reduction of Errors - Centralized information access ensures consistency, minimizes errors, and allows multiple users to rely on the same standard documents and data.
• Secured Remote Access - Secure networks enable safe access to sensitive data from remote locations. Registered mobile devices and multi-layer authentication help prevent unauthorized access.

What is Network Topology?

The structure of the network and how each component is connected to the others are defined by the network topology. Different types of network topology are mentioned below:

Bus Topology

Every computer and network device is connected to a single cable in a bus topology network. Linear Bus topology is defined as having exactly two terminals.

Advantages

• Installation is simple
• Compared to mesh, star, and tree topologies, the bus utilizes less cabling

Disadvantages

• Difficulty in reconfiguring and isolating faults
• A bus cable malfunction or break interrupts all communication

For more, you can refer to the Advantages and Disadvantages of Bus Topology.

Ring Topology

The topology is named ring topology because one computer is connected to another, with the final one being connected to the first. Exactly two neighbors for each device. A signal is passed along the ring in one direction. Each ring incorporates a repeater. 

Advantages

• Data transmission is relatively straightforward because packets only move in one direction
• There is no requirement for a central controller to manage communication between nodes
• Easy installation & Reconfiguration
• Simplified Faulty connections

Disadvantages

• In a Unidirectional Ring, a data packet must traverse through all nodes
• All computers must be turned on in order for them to connect with one another

For more, you can refer to the Advantages and Disadvantages of Ring Topology.

Star Topology

Each device in a star topology has a dedicated point-to-point link to a central controller, which is commonly referred to as the HUB. There is no direct connection between the devices. Traffic between the devices is not allowed in this topology. As an exchange, the controller is used.

Advantages

• When attaching or disconnecting devices, there are no network interruptions
• It's simple to set up and configure
• Identifying and isolating faults is simple
• Less Expensive than mesh 
• Easy to install & configure

Disadvantages

• Nodes attached to the hub, switch, or concentrator is failed if they fail
• Because of the expense of the hubs, it is more expensive than linear bus topologies
• More cable is required compared to a bus or ring 
• Too much dependency on Hub

For more, you can refer to the Advantages and Disadvantages of Star Topology.

Example: Used in high-speed LANs

Mesh Topology

Every device in a mesh topology has dedicated point-to-point connectivity to every other device. The term "dedicated" refers to the fact that the link exclusively transports data between the two devices it links. To connect n devices, a fully connected mesh network contains n *(n-1)/2 physical channels.

Advantages

• Data can be sent from multiple devices at the same time. This topology can handle a lot of traffic.
• Even if one of the connections fails, a backup is always available. As a result, data transit is unaffected.
• Physical boundaries prevent other users from gaining access to messages.
• Point to Point links make fault transmission & fault isolation easy.

Disadvantages

• The amount of cabling and the number of I/O ports that are necessary.
• The sheer bulk of wiring can be greater than the available space can accommodate.
• It is difficult to install and reconfigure.

For more, you can refer to the Advantages and Disadvantages of Mesh Topology.

Example:  connection of telephone regional office in which each regional office needs to be connected to every other regional office. 

Tree Topology

The topology of a tree is similar to that of a star. Nodes in a tree, like those in a star, are connected to a central hub that manages network traffic. It has a root node, which is connected to all other nodes, producing a hierarchy. Hierarchical topology is another name for it. The number of Star networks is connected via Bus in Tree Topology.

Advantages

• Network expansion is both possible and simple.
• We partition the entire network into pieces (star networks) that are easier to manage and maintain.
• Other segments are unaffected if one segment is damaged.

Disadvantages

• Tree topology relies largely on the main bus cable because of its basic structure, and if it fails, the entire network is handicapped.
• Maintenance becomes more challenging when more nodes and segments are added.

For more, you can refer to the Advantages and Disadvantages of Tree Topology.

Introduction to Computer Networks

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