14.8.1 What Is a Computer Network and Why Do We Need One?
- What Is a Computer Network?
- Why Were Computer Networks Developed?
- What Are the Benefits of Networking?
- What Resources Can Be Shared?
- How Do Devices Communicate?
- What Types of Networks Exist?
- How Is Networking Different from Internetworking?
- Why Have Networks Become So Important?
- How Have Networks Changed Over Time?
- What Makes Modern Networks Possible?
- Will Networks Continue to Grow?
- Why Is Understanding Networks Important?
- What Should You Remember?
Short Answer
A computer network is a collection of computers, communication devices, and other equipment connected so they can exchange information and share resources. Networking allows users to communicate, access shared files and applications, use common printers and storage devices, and connect to the Internet. Today, virtually every communication service—from email and video streaming to cloud computing and online banking—depends upon computer networks.
What Is a Computer Network?
A computer network consists of two or more devices connected by communication links that allow them to exchange information.
The devices connected to the network may include:
- desktop computers;
- laptops;
- smartphones;
- servers;
- printers;
- storage systems;
- sensors; and
- industrial equipment.
The communication links may use:
- twisted-pair copper cable;
- fiber-optic cable;
- radio;
- microwave;
- satellite; or
- other transmission media.
Regardless of the physical technology, the objective remains the same—to allow devices to communicate efficiently and reliably.
Why Were Computer Networks Developed?
Before networking became widespread, computers operated largely in isolation.
Users stored information locally, and transferring data between computers often required removable media such as floppy disks or magnetic tapes. This approach created many practical problems. Files became difficult to share, software had to be installed on every computer individually, and expensive peripherals such as printers could not easily be shared.
Networking solved these problems by allowing computers to communicate directly with one another.
What Are the Benefits of Networking?
Modern networks provide many advantages.
They allow users to:
- share files and documents;
- communicate rapidly;
- access common printers and storage devices;
- share Internet connections;
- collaborate on projects;
- centralize software and data management;
- improve data backup and recovery; and
- access cloud-based services.
Without networking, many of the services people now take for granted would be impractical.
What Resources Can Be Shared?
One of the primary purposes of networking is resource sharing.
Examples include:
- printers;
- file servers;
- databases;
- Internet access;
- application software;
- network storage;
- multimedia content; and
- processing resources.
Rather than providing every user with separate equipment, organizations can share expensive resources efficiently across the network.
This significantly reduces both cost and administration.
How Do Devices Communicate?
Communication between network devices follows agreed sets of rules known as protocols.
Protocols specify:
- how information is formatted;
- how devices identify one another;
- how errors are detected;
- how lost information is recovered; and
- how communication sessions are established and terminated.
Because every device follows the same protocols, equipment manufactured by different companies can communicate successfully.
Standardization has therefore been fundamental to the growth of modern networking.
What Types of Networks Exist?
Networks vary enormously in size.
Examples include:
- Personal Area Networks (PANs) connecting devices over a few metres;
- Local Area Networks (LANs) within homes, offices, or campuses;
- Metropolitan Area Networks (MANs) covering cities; and
- Wide Area Networks (WANs) spanning countries and continents.
Although these networks differ greatly in scale, they all perform the same basic function—transferring information between connected devices.
How Is Networking Different from Internetworking?
A network is a collection of interconnected devices operating together.
Internetworking goes one step further. It connects multiple independent networks into a much larger system. The Internet is the world's largest example of internetworking. It links millions of separate networks operated by universities, businesses, governments, telecommunications providers, and individuals into one global communication system.
This chapter focuses primarily on networking within individual networks, while the next chapter examines how separate networks are interconnected.
Why Have Networks Become So Important?
The rapid growth of digital technology has dramatically increased the importance of networking.
Modern society depends on networks for:
- electronic commerce;
- cloud computing;
- online education;
- video conferencing;
- streaming entertainment;
- industrial automation;
- financial services; and
- healthcare.
Increasingly, information is created, stored, and processed across distributed networks rather than on individual computers.
How Have Networks Changed Over Time?
Early computer networks were relatively small and supported only modest data rates.
Many connected only a few computers within a single building. Advances in communication technology—including fiber-optic transmission, packet switching, Ethernet, Wi-Fi, and high-speed routing—have enabled networks to expand enormously. Today, many organizations operate global networks connecting thousands of sites and millions of users.
At the same time, wireless networking has made network access almost ubiquitous.
What Makes Modern Networks Possible?
Several communication technologies work together to make modern networking possible.
These include:
- digital transmission;
- packet switching;
- high-speed optical fiber;
- Ethernet;
- Wi-Fi;
- Internet Protocol (IP); and
- sophisticated routing and switching equipment.
Together, these technologies allow information to move rapidly and reliably between users almost anywhere in the world.
Will Networks Continue to Grow?
Almost certainly.
Several trends continue to increase demand for networking. These include:
- cloud computing;
- artificial intelligence;
- the Internet of Things (IoT);
- smart cities;
- autonomous vehicles;
- industrial automation;
- virtual and augmented reality; and
- integrated terrestrial and satellite communication systems.
As these technologies mature, networks will continue expanding in both size and capability.
Why Is Understanding Networks Important?
Communication systems transport information over individual links.
Networking explains how those links are organized into complete communication systems that allow millions of devices to exchange information simultaneously. Understanding networking provides the foundation for studying:
- routing;
- addressing;
- switching;
- network management;
- cybersecurity; and
- the Internet itself.
These concepts underpin virtually every modern communication system.
What Should You Remember?
- A computer network is a collection of interconnected devices that exchange information and share resources.
- Networking enables communication, collaboration, centralized services, and efficient resource sharing.
- Networks may use wired or wireless communication technologies and range from personal-area networks to global wide-area networks.
- Communication is governed by standardized protocols that allow equipment from different manufacturers to interoperate.
- Modern society depends heavily on computer networks for business, education, entertainment, healthcare, and government services.
- Networking concerns communication within a network, while internetworking connects many independent networks together.
- Understanding networking provides the foundation for understanding the Internet and modern digital communication systems.