Computer networks: LANs, WANs and the internet

விளையாடிக் கற்றுக்கொள்ளுங்கள்

ஆற்றல் சம்பாதிக்க இந்த கேள்விகளுக்குப் பதிலளியுங்கள், பின்னர் மீன் பிடித்து ஆராயுங்கள். கணக்கு தேவையில்லை.

கல்வியாளர்களுக்கு: Computer networks: LANs, WANs and the internet (KS3 Computing, Computer Systems)-க்கான தயாரான பாட ஸ்லைடுகள், திருப்புதல் குறிப்புகள், வரைபடங்கள் — உங்கள் பாடத்தில் அவற்றைப் பயன்படுத்தவும், அல்லது கற்பவர்கள் நேரலை விளையாட்டாக விளையாடும் ஊடாடும் வகுப்பு செயல்பாடாக தலைப்பை இயக்கவும்.

பாட குறிப்புகள்

Why Network Computers?

Networks let computers and peripherals (hosts) communicate and share data.
They support services like the World Wide Web, email, instant messaging, digital video/audio, and shared printers.
Many applications have limited functionality without a network connection.
Networks allow resource sharing (e.g., storage servers, applications).
They enable remote access to computers and data.

LANs and WANs

A Local Area Network (LAN) covers a small area, like a home, school, or office.
A Wide Area Network (WAN) spans a large geographical area, often connecting multiple LANs.
The internet is the largest WAN, connecting networks worldwide.
LANs are usually owned and managed by a single organisation, while WANs may be owned by multiple providers.
WANs often use leased telecommunication lines or satellite links.

Wired and Wireless Connections

Wired connections use physical media like copper cables (e.g., Ethernet) or optical fibres.
Wireless connections use radio-frequency signals, such as Wi-Fi and Bluetooth.
Wired connections generally offer faster and more stable speeds.
Wireless connections provide mobility and easier setup.
The choice depends on factors like speed, reliability, and convenience.

Wired networks use cables and are fast and reliable; wireless uses radio waves and is convenient and flexible.

Network Hardware

Routers forward data packets between different networks, e.g., a home LAN to the internet.
Switches connect devices within a LAN, directing data to the correct device.
Servers provide resources or services to other computers (clients) on the network.
Hosts are any devices that send or receive data, such as computers, printers, or smartphones.
Modems (like the Bell 101) modulate/demodulate signals for transmission over telephone lines.

A switch receives a data packet on one port and forwards it only to the destination port.

The Internet as a Global Network

The internet is a global network of networks that connects millions of devices.
It evolved from the ARPANET, which began in 1969 with four nodes.
The internet uses packet switching to send data in small chunks.
It relies on communication protocols (like TCP/IP) to ensure data is sent and received correctly.
The internet enables services like the World Wide Web, email, and streaming.

How Systems Communicate

Each host on a network has a network address (e.g., IP address) that identifies it.
Hosts may also have hostnames (like www.example.com) that are easier to remember.
A name server (e.g., Domain Name System) maps hostnames to network addresses.
Data is transmitted using communication protocols that define rules for exchange.
Packet switching breaks data into packets that travel independently and are reassembled at the destination.

Network Topologies

Network topology is the arrangement of hosts and hardware in a network.
Common topologies include bus, star, ring, and mesh.
In a star topology, all devices connect to a central switch or hub.
In a mesh topology, devices connect to many others, providing redundancy.
Topology affects performance, cost, and reliability.

In a star topology every device connects to a central switch using its own cable.

History of Networks

The first computer network was created in 1940 when George Stibitz connected a terminal to a computer at Bell Labs.
The SAGE radar system in the late 1950s used the first commercial modem (Bell 101) at 110 bit/s.
Packet switching was invented independently by Paul Baran and Donald Davies in the 1960s.
The ARPANET (1969) was the first network to use packet switching and became the basis for the internet.
Ethernet was developed by Robert Metcalfe at Xerox PARC in 1973.

A home network: the broadband line reaches a modem, then a router, a switch and a wireless access point serve the devices.

A message is split into numbered packets that may take different routes and are reassembled in order at the destination.

ஸ்லைடுகள்

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பதிவு செய்க — இலவசம்உள்நுழைக

பயிற்சி கேள்விகள்

இலவச முன்னோட்டம் — 60-இல் 8 கேள்விகள். அனைத்தையும் பார்க்க பதிவு செய்யவும்.

1.A computer network is a group of communicating computers and peripherals known as hosts.
Easy
True or false?
2.What is the name for the memorable labels that can be mapped to a network address using a hosts file or a name server?
Easy
- AHostnames
- BIP addresses
- CProtocols
- DTopologies
3.Which of the following are examples of physical media that support information exchange in a computer network? (Select all that apply)
Easy
- ACopper cables
- BOptical fibres
- CRadio-frequency media
- DRouters
- EHostnames
4.A WAN (Wide Area Network) typically covers a smaller geographical area than a LAN (Local Area Network).
Easy
True or false?
5.Which device is used to connect a local network to the internet and route data between networks?
Easy
- ARouter
- BSwitch
- CServer
- DModem
6.Match each network term to its correct definition.
Medium
- LAN
- WAN
- Router
- Connects devices over a large geographical area
- Connects devices within a limited area like a school
- Device that forwards data between networks
7.Packet switching was independently invented by Paul Baran and Donald Davies.
Medium
True or false?
8.Match each network component to its primary function.
Easy
- Router
- Switch
- Server
- Connects different networks and routes data
- Connects devices within a single network
- Provides resources or services to clients

மேலும் கேள்விகள்

9.Put the following events in chronological order, from earliest to latest.
Medium
- George Stibitz connects a terminal to a computer over a distance
- The Bell 101 modem is released
- ARPANET's first four nodes are connected
- The NPL network is implemented
10.Which of the following are examples of network topologies? (Select all that apply)
Medium
- ABus
- BStar
- CMesh
- DHTTP
- ETCP/IP
11.A LAN (Local Area Network) typically covers a smaller geographical area than a WAN (Wide Area Network).
Easy
True or false?
12.Which of the following is a wireless medium for transmitting data in a network?
Easy
- ACopper cable
- BOptical fiber
- CRadio-frequency waves
- DTwisted pair
13.Which of the following are services that networks commonly support? (Select all that apply)
Medium
- AAccess to the World Wide Web
- BDigital video and audio streaming
- CEmail and instant messaging
- DWord processing software installation
- EPrinting from a shared printer
14.A student connects two computers using a copper cable so they can share files. What type of network have they created?
Easy
- ALAN
- BWAN
- CInternet
- DPAN
15.The internet is a single large network that connects all computers directly to each other.
Easy
True or false?
16.Which of the following are examples of services that networks commonly support? (Select all that apply)
Medium
- AAccess to the World Wide Web
- BDigital video and audio streaming
- CUsing a printer over the network
- DSending email
- ERunning a standalone calculator app
17.A company has offices in London and New York. They need to connect their local networks so employees can share resources. Which type of network would connect these two LANs?
Hard
- ALAN
- BWAN
- CPAN
- DMAN
18.The first computer network was created in 1940 by George Stibitz.
Easy
True or false?
19.The physical medium that supports information exchange in a network can be wired or wireless.
Easy
True or false?
20.Which of the following best describes the role of a router in a computer network?
Hard
- AIt connects a local network to the internet and routes data between networks.
- BIt provides storage and services to other devices on the network.
- CIt converts digital data into analog signals for transmission over telephone lines.
- DIt identifies hosts on a network using memorable labels.
21.The NPL network, developed at the National Physical Laboratory in the UK, pioneered the implementation of packet switching using 768 kbit/s links.
Medium
True or false?
22.Which of the following statements about the ARPANET is correct?
Medium
- AIt was the first network to use packet switching.
- BIt began in 1969 with four nodes connected by 50 kbit/s circuits.
- CIt was designed by George Stibitz.
- DIt was the first commercial modem for computers.
23.In computer networking, a host is any device that communicates with other devices on the network.
Easy
True or false?
24.Network addresses are used to identify hosts within a computer network.
Easy
True or false?
25.The first computer network was created by George Stibitz in 1940.
Easy
True or false?
26.The internet is a single network that connects all computers directly to each other.
Easy
True or false?
27.Packet switching was invented independently by Paul Baran and Donald Davies.
Easy
True or false?
28.The Bell 101 modem was the first commercial modem for computers.
Easy
True or false?
29.Which of the following is a wired medium for transmitting data in a network?
Easy
- ACopper cable
- BRadio waves
- CInfrared
- DBluetooth
30.Which type of network typically covers a small geographical area, such as a single building or campus?
Medium
- ALAN
- BWAN
- CInternet
- DPAN
31.Which of the following is a service that networks commonly support?
Medium
- AAccess to the World Wide Web
- BBaking bread
- CGrowing plants
- DPainting walls
32.In 1958, the Bell 101 modem allowed digital data to be transmitted over telephone lines at what speed?
Medium
- A110 bits per second
- B110 bytes per second
- C110 kilobits per second
- D110 megabits per second
33.The ARPANET was the first network to use packet switching.
Easy
True or false?
34.Match each network type to its typical geographical coverage.
Easy
- LAN
- WAN
- Covers a small area like a single building or campus
- Covers a large area, often spanning cities, countries, or even the globe
35.Put the following network milestones in chronological order, from earliest to latest.
Medium
- George Stibitz demonstrates remote use of a computer
- Bell 101 modem released
- ARPANET first four nodes connected
- NPL network pioneers packet switching
36.Which of the following are examples of wired media used in computer networks? (Select all that apply)
Easy
- ACopper cables
- BOptical fibres
- CRadio waves
- DMicrowaves
- EInfrared
37.A company has offices in London and New York. They need to connect their local networks so employees can share resources. Which type of network would connect these two offices?
Medium
- ALAN
- BWAN
- CPAN
- DMAN
38.A school has two buildings 200 metres apart. They want to connect the computers in both buildings using a network. Which type of network would this be?
Easy
- ALAN
- BWAN
- CPAN
- DMAN
39.Which of the following are true about the ARPANET? (Select all that apply)
Medium
- AIt began in 1969.
- BThe first four nodes were connected using 50 kbit/s circuits.
- CIt was designed by Bob Kahn.
- DIt was the first network to use packet switching.
- EIt connected the first international heterogeneous computer network.
40.A network address is a memorable label for a host that can be mapped to a hostname.
Easy
True or false?
41.Fill in the blank: The arrangement of hosts and hardware within a network architecture is known as the network ___.
Easy
The arrangement of hosts and hardware within a network architecture is known as the network ____.
42.What does LAN stand for?
Medium
43.Fill in the blank: The internet is a global network of ___.
Easy
The internet is a global network of ____.
44.In 1958, the Bell 101 modem allowed digital data to be transmitted at what speed (in bits per second)?
Medium
45.What was the transmission speed of the Bell 101 modem, in bits per second?
Easy
46.Complete the sentence about network identification.
Medium
Each host on a network is identified by a unique ____ and may also have a memorable ____.
47.What is the name of the concept invented independently by Paul Baran and Donald Davies that involves breaking data into blocks for transmission across a network?
Medium
48.What was the name of the first computer network, created in 1940, and who created it?
Medium
49.Fill in the blanks to complete the sentence about the internet.
Medium
The internet is a global network of ____ that connects millions of ____ devices worldwide.
50.In 1958, the Bell 101 modem transmitted digital data at a speed of 110 bits per second. How many bits could it transmit in 10 seconds?
Medium
51.George Stibitz's 1940 demonstration used a teletype connected to a computer at Bell Labs. What type of medium carried the data between the two locations?
Medium
52.Complete the sentence about the first computer network.
Medium
The first computer network was created in ____ when George Stibitz connected a terminal at Dartmouth to his Complex Number Calculator at Bell Labs.
53.Explain why computers are often connected in a network. Give one reason.
Medium
54.Explain why packet switching is considered a more efficient method for data transmission than circuit switching in modern networks.
Hard
55.Explain why the invention of packet switching was important for the development of computer networks.
Medium
56.Explain why packet switching is considered more efficient than circuit switching for transmitting data over a network. Refer to how data is handled in each method.
Hard
57.Explain how the inventions of Paul Baran and Donald Davies contributed to the development of computer networks, and why their ideas were important for the internet.
Hard
58.In 1958, the Bell 101 modem allowed digital data to be transmitted at what speed (in bits per second)?
Medium
- A132 bit/s
- B121 bit/s
- C110 bit/s
- D99 bit/s
59.What was the transmission speed of the Bell 101 modem, in bits per second?
Easy
- A132 bit/s
- B99 bit/s
- C121 bit/s
- D110 bit/s
60.In 1958, the Bell 101 modem transmitted digital data at a speed of 110 bits per second. How many bits could it transmit in 10 seconds?
Medium
- A990 bits
- B1320 bits
- C1210 bits
- D1100 bits

திருப்புதல் குறிப்புகள்

## Computer Networks: LANs, WANs and the Internet ### Why Network Computers? - **Share resources**: printers, files, internet connections. - **Communicate**: email, instant messaging, video calls. - **Access services**: World Wide Web, cloud storage, online games. - **Collaborate**: work together on documents in real time. ### LANs and WANs - **LAN (Local Area Network)**: A network that covers a small area, like a school, office, or home. Usually owned and managed by one organisation. - **WAN (Wide Area Network)**: A network that spans a large geographical area, often connecting multiple LANs. The internet is the largest WAN. ### Wired and Wireless Connections - **Wired**: Use physical cables (e.g., copper cables, optical fibres). Faster and more secure, but less flexible. - **Wireless**: Use radio waves (e.g., Wi-Fi, Bluetooth). Convenient and portable, but can be slower and less secure. ### Network Hardware - **Router**: Connects different networks together (e.g., your home network to the internet). Routes data between them. - **Switch**: Connects devices within a single network (e.g., computers in a school lab). Sends data only to the intended device. - **Server**: A powerful computer that provides services or resources to other computers (clients) on the network, such as storing files or hosting websites. ### The Internet - The internet is a **global network of networks**. It connects millions of devices worldwide. - Devices communicate using **communication protocols** (rules for sending and receiving data). - Each device has a **network address** (like an IP address) so data can be sent to the right place. Hostnames (like www.example.com) are easier to remember and are translated to addresses by the **Domain Name System (DNS)**. ### How Systems Communicate - Data is broken into small chunks called **packets** and sent across the network. - **Packet switching** is the method used: packets travel independently and are reassembled at the destination. - The **physical medium** can be wired (copper, fibre) or wireless (radio waves). ### Key Points to Remember - The first computer network was created in 1940 by George Stibitz. - The ARPANET, started in 1969, was the precursor to the internet. - Ethernet, invented in 1973, is a common technology for LANs.

Network: A group of communicating computers and peripherals known as hosts, which communicate data to other hosts via communication protocols, as facilitated by networking hardware.
Host: A computer or peripheral on a network that sends or receives data.
Network address: An identifier that allows networking hardware to locate and identify hosts on a network.
Hostname: A memorable label for a host node, which can be mapped to a network address using a hosts file or a name server such as Domain Name Service.
Communication protocol: A set of rules that enables hosts to communicate data to each other.
Networking hardware: Physical devices (e.g., routers, switches) that facilitate communication in a network.
LAN (Local Area Network): A network that connects computers and devices within a limited area, such as a school or office.
WAN (Wide Area Network): A network that spans a large geographical area, often connecting multiple LANs. The internet is the largest WAN.
Router: A device that connects different networks together and routes data between them.
Switch: A device that connects devices within a single network and sends data only to the intended device.
Server: A computer that provides services or resources to other computers (clients) on a network.
Internet: A global network of networks that connects millions of devices worldwide.
Packet switching: A method of data transmission where data is broken into packets that travel independently and are reassembled at the destination.
Domain Name System (DNS): A system that translates hostnames (like www.example.com) into network addresses (like IP addresses).
Physical medium: The material or channel that carries data, such as copper cables, optical fibres, or wireless radio-frequency media.

ஃப்ளாஷ் கார்டுகள்

What is a computer network?

A group of communicating computers and peripherals, known as hosts, that exchange data using communication protocols and networking hardware.

What is a host in a computer network?

A host is a computer or peripheral device that communicates with other hosts on a network.

What are network addresses used for?

Network addresses identify hosts on a network, allowing networking hardware to locate and communicate with them.

What is a hostname?

A hostname is a memorable label for a host node, which can be mapped to a network address using a hosts file or a name server like DNS.

What physical media can support network communication?

Wired media like copper cables and optical fibers, and wireless radio-frequency media.

What is network topology?

The arrangement of hosts and hardware within a network architecture.

What was the first computer network and when was it created?

In 1940, George Stibitz connected a terminal at Dartmouth to his Complex Number Calculator at Bell Labs, creating the first remote use of a computing machine.

What is a LAN?

A Local Area Network (LAN) is a network that connects computers and devices in a limited geographical area, such as a home, school, or office.

What is a WAN?

A Wide Area Network (WAN) spans a large geographical area, often connecting multiple LANs. The internet is the largest example of a WAN.

What is the internet?

The internet is a global network of networks that connects millions of computers worldwide, enabling communication and access to services like the World Wide Web.

What is a router?

A router is a network device that forwards data packets between different networks, directing traffic on the internet.

What is a switch?

A switch is a network device that connects devices within a LAN, forwarding data only to the intended device.

What is a server?

A server is a computer that provides services or resources to other computers (clients) on a network, such as storing files or hosting websites.

What are wired connections?

Wired connections use physical cables, such as Ethernet cables, to transmit data between devices.

What are wireless connections?

Wireless connections use radio waves to transmit data without physical cables, such as Wi-Fi and Bluetooth.

Why do we network computers?

To share resources (like printers and files), communicate (email, messaging), and access the internet and other services.

What is packet switching?

A method of data transmission where data is broken into packets, sent independently over a network, and reassembled at the destination. It was invented independently by Paul Baran and Donald Davies in the 1960s.

What was the ARPANET?

The ARPANET was an early packet-switched network, the precursor to the internet, first connecting four nodes in 1969.

What is Ethernet?

Ethernet is a local area networking technology invented by Robert Metcalfe and David Boggs at Xerox PARC in 1973.

What is DNS (Domain Name System)?

DNS is a system that translates human-friendly hostnames (like www.example.com) into network addresses (IP addresses) so that computers can locate each other.

What is a modem?

A modem modulates and demodulates signals to transmit digital data over analog lines, such as telephone lines. The Bell 101 was the first commercial modem in 1958.

What is the role of communication protocols?

Communication protocols are rules that define how data is transmitted and received over a network, ensuring devices can understand each other.

What is the end-to-end principle?

The principle that the network should be simple and reliable, while the hosts (endpoints) are responsible for ensuring reliable data delivery. It was a key idea in CYCLADES and the internet.

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இந்த தலைப்பிற்கான ஒவ்வொரு கேள்வியையும், ஸ்லைடுகளையும், ஃப்ளாஷ் கார்டுகளையும் மற்றும் திருப்புதல் குறிப்புகளையும் பார்க்க இலவச கணக்கை உருவாக்கவும்.

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