Unit 5 Session 1: Importance of Communication and Networking | IT 231 BBA Slides

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Unit 5 · Session 1

Importance of Communication and Networking

IT 231: IT and Applications (BBA)

🎯 Learning Objectives

By the end of this session, you will be able to:

  • ✅ Define data communication and computer networking.
  • ✅ Explain why networking is a critical field in modern Information Technology.
  • ✅ Identify the key topics we will explore in this unit, including network types, protocols, and wireless technology.
  • ✅ Recognize the fundamental components that enable network communication.

Communication and Networking

The Big Picture: An Interconnected World

In today's world, nearly every aspect of our lives is connected. Networking is the invisible backbone that makes this possible.

Think about it: How many times have you used a network today?

  • Checking social media on your phone? (Wireless Network)
  • Sending an email from your laptop? (Internet)
  • Printing a document in the computer lab? (Local Area Network)

This unit explores how all of this works.

What are Communication & Networking?

At its core, networking is about connection and information sharing.

We will explore two fundamental concepts:

📊 Data Communication

The process of transferring digital data between two or more points. It's the "how" of data movement.

🌐 Computer Networking

The practice of linking two or more computing devices together for the purpose of sharing resources.

📦 The Five Components of Data Communication

Every exchange of data, from a text message to a bank transfer, needs the same five parts:

ComponentWhat it isExample: sending a WhatsApp photo
1. SenderThe device that sends the dataYour phone
2. ReceiverThe device that gets the dataYour friend's phone
3. MessageThe data itselfThe photo
4. MediumThe path the data travels alongWi-Fi, mobile signal and fibre cables
5. ProtocolThe rules both sides agree onThe rules that package, send and check the photo

If any one of the five is missing, communication fails.

🎯 Activity: Spot the Five Components

In pairs, name the sender, receiver, message, medium and protocol in each case.

A. You pay a shopkeeper by scanning a QR code

  • Sender: your phone's wallet or banking app
  • Receiver: the payment company's server, which then alerts the shop
  • Message: the payment instruction (amount and account)
  • Medium: mobile data or Wi-Fi, then fibre cables
  • Protocol: secure payment rules both sides follow

B. Your lecturer teaches a live online class

  • Sender: the lecturer's laptop, camera and microphone
  • Receiver: every student's phone or laptop
  • Message: live video and audio
  • Medium: home Wi-Fi, fibre and mobile signals
  • Protocol: the video app's streaming rules

Bonus: The video freezes. Which component is most likely the problem? Usually the medium, such as a weak signal.

Why Networking Matters ⚡

Networking is one of the most important fields in IT. Here's why:

  • Resource Sharing: Share files, printers, and scanners across multiple devices.
  • Information Access: Provides access to the vast information on the internet.
  • Communication: Enables email, video conferencing, and instant messaging.
  • E-commerce & Business: Powers online shopping, banking, and global business operations.

Key Takeaway: Without networking, the modern digital world as we know it would not exist.

🎬 Who Runs the Internet?

🕰️ A Short History of Networking

1969ARPANET sends its first message, from UCLA to the Stanford Research Institute. The system crashed after two letters: "LO".
1974Vint Cerf and Bob Kahn publish the design for TCP, the rules that let different networks talk to each other.
1983ARPANET switches to TCP/IP on 1 January. Many call this the birthday of the internet.
1989–91Tim Berners-Lee invents the World Wide Web at CERN, and the first website goes online.
Mid-1990sCommercial email and internet services reach Nepal.
2007The iPhone puts the full web in people's pockets, and smartphones take off.
2019The first commercial 5G mobile networks launch, starting in South Korea.

In about 50 years, networking went from 2 computers to billions of devices.

Hand-drawn 1977 map of the ARPANET: boxes for computers at US universities and labs, joined by lines, with links to Hawaii and London

📈 Who Is Online? The Internet in Numbers

  • About 5.5 billion people use the internet, roughly 68% of the world.
  • About 2.6 billion people are still offline.
  • In cities, 83% are online. In rural areas, only 48%.
  • In high-income countries, 93% are online. In low-income countries, 27%.

Source: ITU, Facts and Figures 2024.

Discuss: This gap is called the digital divide.

  • Why might a business care that half of rural people are offline?
  • Is it a problem, an opportunity, or both?

💥 Case Study: The Day Facebook Disappeared

  • On 4 October 2021, Facebook, Instagram and WhatsApp went offline worldwide for about six hours.
  • The cause was not hackers. During routine maintenance, a command accidentally cut the links between Facebook's data centres.
  • With the network gone, the rest of the internet could no longer find Facebook. Engineers had to go to the data centres in person to fix it.
  • Billions of people lost their main way to message family, and many small shops lost their only sales channel for the day.

Discuss: If your business took every order through one app, what would you do during a six-hour outage? How could you plan for it?

Core Concepts in This Unit

We will break down networking into its essential building blocks:

Network Types & Topologies

How networks are structured (LAN, WAN) and arranged physically/logically.

Protocols & Hardware

The rules (protocols) and physical devices (routers, switches) that make communication possible.

Wireless Networking

The technology behind Wi-Fi, cellular data, and connecting without cables.

🔍 A Closer Look: Network Types

Networks are often categorized by their geographical scope.

LAN (Local Area Network)

Connects devices within a limited area, like a home, school, or office building.

  • High speed
  • Privately owned
  • Example: Your university's computer lab network.

WAN (Wide Area Network)

Spans a large geographical area, such as a city, country, or even the entire globe.

  • Slower than LANs
  • Often uses public infrastructure
  • Example: The Internet is the world's largest WAN.

🎯 Quick-Fire: LAN or WAN?

Call out your answer before each one is revealed.

1. The Wi-Fi network in your homeLAN
2. A bank linking its branches across the countryWAN
3. Your college computer labLAN
4. An airline's booking system linking offices in Kathmandu, Doha and DelhiWAN
5. Casting a video from your phone to a smart TV on the same Wi-FiLAN
6. The internetWAN (the largest one)

Bonus: Your phone's 4G connection? WAN. The mobile operator's network covers the whole country.

Inside a LAN: switches and patch panels

A network rack full of switches and patch panels with neatly bundled grey Ethernet cables

🎬 The World’s Largest WAN Is Under the Sea

🔍 A Closer Look: Protocols

Protocol: A set of rules or procedures for transmitting data between electronic devices.

Think of protocols as the "language" computers use to speak to each other.

🔍 A Closer Look: Protocols (cont.)

Analogy: When you make a phone call, you have a protocol:

  1. You say "Hello?"
  2. The other person responds.
  3. You take turns speaking.
  4. You say "Goodbye" to end the call.

Network protocols (like TCP/IP) do the same for data, ensuring it's sent and received correctly.

🔍 A Closer Look: Wireless Networking

The rise of wireless technology has revolutionized how we connect.

  • Mobility: Connect to the internet from anywhere without being tied down by cables.
  • Convenience: Easy to set up and use for devices like smartphones, laptops, and smart home gadgets.
  • Technologies: We'll explore Wi-Fi, Bluetooth, and cellular networks (4G, 5G).

Wireless isn't "magic" – it uses radio waves to transmit data. We'll learn how this works in a later chapter.

A Wi-Fi router

A black Wi-Fi router with six antennas

🏪 Worked Example: A Supermarket Chain Runs on Networks

Imagine a supermarket chain with 20 branches. Here's every network it uses in a single sale:

  • LAN: the tills, barcode scanners, receipt printers and CCTV in each branch are linked by cable.
  • Wireless: staff check stock with handheld scanners, and customers use guest Wi-Fi.
  • Protocols: a card or QR payment is checked with the bank in a few seconds, following strict security rules.
  • WAN: every sale is sent to head office, which tracks stock and orders more from suppliers.

Think: One branch loses its internet link. What still works, and what stops?

The tills can still scan items over the LAN, but card and QR payments and stock updates stop. That's why shops keep a cash fallback.

Networking in Action: The Nepal Context 🇳🇵

Networking is transforming Nepal's economy and society:

  • Digital Payments: Companies like eSewa and Khalti rely on secure networks to process millions of transactions daily.
  • ISP Growth: The expansion of Internet Service Providers (ISPs) like WorldLink and Vianet is bringing high-speed internet to more homes and businesses.
  • Remote Work & Education: Reliable networking enabled remote work and online classes, especially in urban centers.
  • Challenges: Providing consistent, affordable connectivity to remote, mountainous regions remains a major networking challenge for the country.

One solar-powered tower, one whole valley

A hilly valley in Nepal with scattered houses and a mobile tower on the ridge

💬 Discussion: Connecting the Hills

A village of 300 homes is a day's walk from the nearest road. You're advising an internet provider.

  1. What would you try first: laying cable, building a mobile tower, or using satellite? Why?
  2. Who should pay for it: the provider, the government, or the villagers?
  3. Name two things that would change for a farmer or a student once the village is online.

Next session compares cables, radio and microwave links, so you can answer question 1 properly.

Key Takeaways

Let's summarize the main points from this introduction:

  • 1️⃣ Foundation of Connectivity: Networking allows computers to connect and share resources, forming the backbone of the digital world.
  • 2️⃣ Core Components: The unit will cover data transmission, network types (LAN/WAN), topologies, hardware, and essential protocols.
  • 3️⃣ Wireless Revolution: Wireless networking has fundamentally changed how we access information, offering unprecedented mobility.
  • 4️⃣ Real-World Impact: From global e-commerce to local digital payments in Nepal, networking has a profound and practical impact.

Image & Video Credits

Images

Videos (YouTube)

  • CodeAI (Code.org), "What is the Internet?" (1:47 to 3:10)
  • Vox, "Thin underwater cables hold the internet. See a map of them all." (0:00 to 1:15)

Exam Practice 📝

Short answer

  1. Define data communication. List its five components.
  2. Differentiate between simplex, half-duplex, and full-duplex with examples.
  3. Why is a protocol necessary in data communication?

Long answer

  1. Explain the importance of computer networks for a business organization, with advantages and disadvantages.
  2. Describe the components and characteristics of an effective data communication system.

Revise the answers in the full note linked on the last slide.

Thank You

Questions before we wrap this hour?

Next: Unit 5 · Session 2 — Data Communication Media and Transmission

Course Home · Next session

📖 Read the full note