Networks and Cloud Computing ICSE Class 8: Types of Networks, Internet Terms, Protocols and the Cloud

What Networks and Cloud Computing is about

Weightage: CISCE publishes no question paper, marking scheme or chapter weightage for Class VIII Computer Studies: your school sets and marks the exam. Networks and Cloud Computing sits in the Theme: Networks theme of the CISCE Curriculum for Upper Primary Classes (VI-VIII).Source: CISCE Curriculum for Upper Primary Classes (VI-VIII), RDCD 2016

Key concepts

Network and its components

A computer network is a group of two or more computers and devices connected together so that they can share data and resources (printers, files, internet connection) and communicate.

Components of communication:

• Sender: the device that sends the data (your phone sending a message).
• Receiver: the device that receives it (your friend's phone).
• Medium (channel): the path the data travels along:
• wired: twisted-pair cable (LAN cables), coaxial cable (cable TV), optical fibre (data as light; very fast, long distance);
• wireless: radio waves (Wi-Fi, Bluetooth), microwaves, satellite links.
• The message (the data itself) and the protocol (the rules both sides follow) complete the picture.

Advantages of networks: sharing files and printers; sharing one internet connection; communication (email, chat, video calls); central storage and backup.
Disadvantages: viruses can spread; data can be stolen if not secured; a failure in a central device can stop everyone.

Worked example

When a teacher prints from a laptop to the staff-room printer over Wi-Fi, identify the sender, receiver and medium.

Try it first, then show the solutionSolution

1. Sender: the teacher's laptop. Receiver: the printer.
2. Medium: wireless radio waves (Wi-Fi).

Answer: Laptop, printer, Wi-Fi

Types of networks

Type	Full form	Area covered	Example
PAN	Personal Area Network	around one person, about 10 m	phone connected to wireless earbuds or a smartwatch by Bluetooth
LAN	Local Area Network	one room, building or nearby buildings	the school computer lab; home Wi-Fi
CAN	Campus Area Network	several LANs across a campus (school, university, factory, office park)	a university connecting its library, hostels and departments
MAN	Metropolitan Area Network	a city or town	a city's cable TV network; a bank's branches across one city
WAN	Wide Area Network	a country or the world	the internet; a railway reservation network across India

From smallest to largest: PAN < LAN < CAN < MAN < WAN.

As the area grows, networks usually become more costly to set up and are often owned by many organisations; a LAN is usually owned by one school or family.

Worked example

Classify: (i) a smartwatch synced with a phone (ii) computers in a school lab (iii) the internet (iv) a cable TV network in one city.

Try it first, then show the solutionSolution

1. (i) PAN (ii) LAN.
2. (iii) WAN (iv) MAN.

Answer: (i) PAN (ii) LAN (iii) WAN (iv) MAN

Internet terms (1): addresses and pages

• Internet: a worldwide network of networks open to the public.
• Intranet: a private network inside an organisation that uses internet technology (web pages, email) but is open only to its members, such as a school portal for teachers.
• ISP (Internet Service Provider): a company that provides internet access to users, for a fee.
• IP address: a unique numeric address given to each device on a network, such as 192.168.1.10. In the common IPv4 form it has four numbers from 0 to 255 separated by dots.
• DNS (Domain Name System): translates easy names such as www.example.com into IP addresses, like a phone's contact list turning a name into a number.
• URL (Uniform Resource Locator): the complete address of a page or file on the web. In https://www.example.com/science/plants.html: https is the protocol, www.example.com the domain name, and /science/plants.html the path to the page.
• Webpage: a single document on the web, viewed in a browser.
• Website: a collection of related webpages under one domain, starting from a home page.
• Web portal: a website that acts as a gateway to many services and links in one place, often after logging in (for example, a government services portal or a school's student portal).
• Hypertext: text that contains links to other text or pages.
• Link / hyperlink: a clickable word, image or button that takes you to another page, or another place on the same page.

Worked example

In the URL https://www.greenvalleyschool.in/results/class8.html, name the protocol, the domain name and the path. Which system finds the server's IP address?

Try it first, then show the solutionSolution

1. Protocol: https; domain name: www.greenvalleyschool.in; path: /results/class8.html.
2. DNS converts the domain name into the server's IP address.

Answer: https; www.greenvalleyschool.in; /results/class8.html; DNS

Internet terms (2): devices and bandwidth

Device or term	What it does
MODEM (modulator-demodulator)	converts digital signals from a computer into analogue signals for telephone or cable lines (modulation) and back again (demodulation), connecting you to the ISP
Hub	connects devices in a LAN; sends incoming data to all connected devices (simple, but wastes bandwidth)
Switch	connects devices in a LAN; sends data only to the device it is meant for (smarter and faster than a hub)
Router	connects different networks (such as your home LAN and the internet) and chooses the best path for data; home Wi-Fi routers often include a modem and switch
Gateway	connects networks that use different protocols, translating between them; the entry and exit point of a network

Bandwidth is the maximum amount of data that can be sent through a connection per second, measured in bits per second (kbps, Mbps, Gbps). More bandwidth means faster downloads and smoother video.

Download time ≈ file size in bits ÷ bandwidth. Since 1 byte = 8 bits, a 100 MB file is 800 megabits; at 20 Mbps it takes about 800 ÷ 20 = 40 seconds (ignoring delays).

Worked example

Distinguish between a hub and a switch.

Try it first, then show the solutionSolution

1. Both connect devices in a LAN.
2. A hub sends data to every connected device; a switch sends it only to the intended device, so it is faster and more efficient.

Answer: Hub: to all; switch: only to the intended device.

Protocols

A protocol is a set of rules that devices follow to communicate over a network, deciding how data is formatted, sent, received and checked. Without common rules, devices from different makers could not understand each other.

Protocol	Full form	Purpose (brief)
HTTP	HyperText Transfer Protocol	transfers webpages from web servers to browsers; HTTPS is the secure (encrypted) version, shown by a padlock
FTP	File Transfer Protocol	uploads and downloads files between computers and servers
TCP/IP	Transmission Control Protocol / Internet Protocol	the basic rules of the internet: TCP breaks data into packets, checks that all arrive and puts them back in order; IP gives addresses and routes each packet to the right device
IMAP	Internet Message Access Protocol	lets you read email that stays on the mail server, so the same mailbox shows on phone and computer
SMTP	Simple Mail Transfer Protocol	sends email from your device to the mail server and between mail servers

Sending an email: your app uses SMTP to send it; your friend's app uses IMAP to read it.

Worked example

Name the protocol used when (i) you open a website (ii) you send an email (iii) you read your email on two devices and see the same folders.

Try it first, then show the solutionSolution

1. (i) HTTP (or HTTPS). (ii) SMTP.
2. (iii) IMAP, which keeps messages on the server.

Answer: (i) HTTP (ii) SMTP (iii) IMAP

Cloud computing: storing and sharing

Cloud computing means using computing services (storage, software, processing power) over the internet, on servers owned by a provider, instead of on your own computer. 'The cloud' is simply other people's computers in large data centres.

Examples: online drives for storing files, online document editors, photo backup services, email.

Characteristics:

• On-demand self-service: you get storage or software when you want, without asking anyone.
• Broad network access: use it from anywhere on any device with internet.
• Resource pooling: the provider's servers are shared by many users.
• Scalability (elasticity): you can quickly get more or less space or power.
• Measured service: you pay for what you use (or use a free limit).

Advantages: access files anywhere, any time; no need to buy big storage or powerful hardware; automatic backup (files are safe if your device is lost); easy sharing and collaboration (several people edit one document together); software is updated automatically.

Limitations: needs a good internet connection; privacy and security depend on the provider and on your password; free space is limited.

Storing and sharing a file in a cloud drive:
1. Sign in to the cloud drive.
2. Upload the file (or create it online).
3. Click Share and choose people by email, or create a link.
4. Set the permission: Viewer (read only), Commenter or Editor.
5. Collaborators open the same file; changes are saved automatically and everyone sees the latest version.

Worked example

Your group is writing a science report together from different homes. How does cloud computing help, and which permission should a teacher who only needs to read it get?

Try it first, then show the solutionSolution

1. Store the report in a cloud drive and share it with the group as Editors; all can work on the same document at the same time from anywhere, and it is backed up.
2. The teacher should get Viewer (or Commenter, to leave remarks) permission.

Answer: Shared online editing from anywhere; Viewer (or Commenter) for the teacher.

Networks and Cloud Computing in real life

Each concept, met in an everyday situation. Read the situation, answer the question in your own words, then compare with the model answer. The one-line hook is what to remember.

Topics in this chapter

• Internet Terms, Protocols and Cloud Computing
• Network Components, PAN to WAN, and Network Devices

Networks and Cloud Computing: syntax and key facts

Communication model

1. 1.Sender
2. 2.medium
3. 3.receiver (with a message and a protocol)

Wired or wireless medium.

Network sizes

PAN < LAN < CAN < MAN < WAN

Person, building, campus, city, country or world.

Download time

time (s) ≈ size in MB × 8 ÷ bandwidth in Mbps

1 byte = 8 bits.

URL parts

protocol :// domain name / path, e.g. https://www.example.com/page.html

DNS turns the domain into an IP address.

Email protocols

SMTP sends; IMAP reads (mail stays on server)

HTTP for webpages, FTP for files, TCP/IP for packets.

Networks and Cloud Computing: diagrams to practise

Practise each one on paper: draw it from the checklist, then tick off every label.

How the school exam asks Networks and Cloud Computing

The question patterns to expect, and the method that works for each.

Tricks to remember Networks and Cloud Computing

Short memory aids. Say each one aloud once, then use it on a question the same day.

• PLCMW: 'Please Let Cats Meet Whales'

  PAN, LAN, CAN, MAN, WAN from smallest to largest.

  Use it when: Order of network types.

• Hub shouts, switch whispers

  A hub sends to everyone; a switch sends only to the right device.

  Use it when: Hub versus switch.

• S for Send, I for Inbox

  SMTP sends mail; IMAP reads your inbox.

  Use it when: Email protocols.

• DNS = the internet's phone book

  Look up a name, get a number (IP address).

  Use it when: Role of DNS.

• MOdulate-DEModulate

  MODEM is made from the first letters of its two jobs.

  Use it when: Meaning of MODEM.

Networks and Cloud Computing: exam-level solved questions

Ordered from exam level to HOTS. Cover the solution, write your own, then compare step by step.

Case-study practice (Section B style)

Read the situation, then answer every part. In a school exam set on the board pattern this is a 6-mark question split into 2 + 2 + 2 marks.

Where the marks are

How a typical answer is split into step marks. Show every step: a right final answer alone rarely earns full marks.

Where students lose marks in Networks and Cloud Computing

The slips examiners see most often, and what to write instead.

• ✗Mistake: Calling the internet a LAN

  The internet spans the world: it is a WAN (a network of networks).

  ✓Do this: Ask how large the area is.

  Usually costs: 1 mark.

• ✗Mistake: Mixing up SMTP and IMAP

  SMTP sends mail; IMAP is used to read it.

  ✓Do this: S for Send, I for Inbox.

  Usually costs: 1 mark.

• ✗Mistake: Confusing website and webpage

  A webpage is one document; a website is a collection of related webpages.

  ✓Do this: Page = one; site = many.

  Usually costs: 1 mark.

• ✗Mistake: Forgetting to multiply by 8 in download sums

  File sizes are in bytes; bandwidth is in bits per second.

  Wrong working

  100 MB ÷ 20 Mbps = 5 s

  Right working

  100 × 8 ÷ 20 = 40 s

  ✓Do this: Convert bytes to bits first.

  Usually costs: 1-2 marks.

• ✗Mistake: Calling an intranet the internet

  An intranet is private to an organisation.

  ✓Do this: Intra = inside.

  Usually costs: 1 mark.

Practice questions on Networks and Cloud Computing

Write each answer on paper first. Open the hint only if you are stuck, and the answer only when you have finished.

1. Q1 · 1 mark · MCQExam level

   Which protocol is used to send email?
   (a) HTTP
   (b) FTP
   (c) SMTP
   (d) IMAP

   Hint

   S for Send.

   Answer

   (c)

2. Q2 · 1 mark · Very short answerExam level

   Name the device that converts digital signals to analogue signals and back.

   Hint

   Modulator-demodulator.

   Answer

   MODEM.

3. Q3 · 2 marks · Short answerExam level

   Define (i) website (ii) hyperlink.

   Hint

   Many pages; clickable.

   Answer

   (i) A collection of related webpages under one domain name. (ii) A clickable word, image or button that takes the user to another page or place.

4. Q4 · 2 marks · Short answerExam level

   Give two advantages of networking computers in a school.

   Hint

   Sharing.

   Answer

   Sharing printers and one internet connection; sharing files and central backup; communication through email or messages (any two).

5. Q5 · 1 mark · Assertion-reasonHarder exam level

   Assertion (A): A switch makes a LAN more efficient than a hub.
   Reason (R): A switch sends data only to the device for which it is meant.
   (a) (A) is true and (R) is false.
   (b) (A) is false and (R) is true.
   (c) Both (A) and (R) are true, and (R) is the correct explanation for (A).
   (d) Both (A) and (R) are true, but (R) is not the correct explanation for (A).

   Hint

   To one, not all.

   Answer

   (c)

6. Q6 · 2 marks · Short answerHarder exam level

   What is bandwidth? How long would a 250 MB file take to download at 25 Mbps (ignoring delays)?

   Hint

   × 8 first.

   Answer

   Bandwidth is the maximum data that can pass through a connection per second (in bits per second). 250 × 8 = 2000 megabits; 2000 ÷ 25 = 80 seconds.

7. Q7 · 2 marks · Short answerHarder exam level

   Distinguish between internet and intranet (two points).

   Hint

   Public or private.

   Answer

   The internet is a public, worldwide network open to everyone; an intranet is a private network within an organisation, open only to its members (usually with a login).

8. Q8 · 2 marks · Short answerHarder exam level

   Explain TCP/IP briefly.

   Hint

   Packets and addresses.

   Answer

   TCP breaks data into packets, checks they all arrive and reassembles them in order; IP gives each device an address and routes the packets to the correct destination.

9. Q9 · 3 marks · Short answerHarder exam level

   State three characteristics of cloud computing.

   Hint

   Anywhere, on demand, scalable.

   Answer

   Any three: on-demand self-service; broad network access from anywhere; resource pooling; scalability (rapid elasticity); measured service (pay for what you use).

10. Q10 · 3 marks · Short answerHarder exam level

    List the steps to share a document in a cloud drive so that a classmate can edit it but a teacher can only view it.

    Hint

    Upload, share, permissions.

    Answer

    Sign in and upload (or create) the document; click Share; add the classmate's email with Editor permission; add the teacher's email with Viewer permission (or share a view-only link); send.

11. Q11 · 2 marks · Short answerHarder exam level

    How long does a 2 GB game update take to download at 40 Mbps (1 GB = 1024 MB, ignoring delays)?

    Hint

    GB → MB → megabits.

    Answer

    2 × 1024 = 2048 MB = 16 384 megabits; 16 384 ÷ 40 = 409.6 seconds (about 6.8 minutes).

12. Q12 · 3 marks · Short answerHOTS / competency

    When you type a URL in a browser, describe in order the roles of DNS, the ISP, TCP/IP and HTTP in getting the page to your screen.

    Hint

    Name → address → connection → page.

    Answer

    Your ISP connects your device to the internet. DNS converts the domain name in the URL into the server's IP address. The browser requests the page using HTTP; TCP/IP breaks the request and the page into packets, routes them between your device and the server and reassembles them, and the browser displays the page.

13. Q13 · 3 marks · Short answerHOTS / competency

    A village school has slow, unreliable internet. Should it move all its records to the cloud? Give a balanced answer with two points for and two against.

    Hint

    Benefits versus needing internet.

    Answer

    For: records are backed up safely even if a computer fails; teachers can access them from anywhere. Against: with slow or unreliable internet, staff may be unable to open records when needed; privacy depends on strong passwords and the provider. A sensible plan is to keep local copies and sync to the cloud when the connection is available.

Test your recall

Answer in your head or on paper first, then open the card. Pulling an answer out of memory makes it stick far better than re-reading.

1. 1.Define protocol.Show answer

   A set of rules for communication between devices on a network.

2. 2.Full form of MODEM?Show answer

   Modulator-demodulator.

3. 3.Which network covers a city?Show answer

   MAN.

4. 4.What does DNS do?Show answer

   Converts domain names into IP addresses.

5. 5.Unit of bandwidth?Show answer

   Bits per second (for example, Mbps).

6. 6.Which protocol transfers webpages?Show answer

   HTTP (HTTPS when secure).

7. 7.Name one cloud storage use.Show answer

   Backing up photos or sharing documents in an online drive.

8. 8.What is a web portal?Show answer

   A website that is a gateway to many services and links in one place.

Quick revision checklist

The night before the exam: can you do each of these without looking?

• ☐Can you name the sender, receiver and medium in any example?
• ☐Can you arrange and give examples of the five network types?
• ☐Can you explain the parts of a URL?
• ☐Can you distinguish hub, switch, router, modem and gateway?
• ☐Can you match each protocol to its job?
• ☐Can you list three advantages and one limitation of cloud computing?

Networks and Cloud Computing: frequently asked questions