Internet and Web
Class 12 · Informatics Practices
4 ideas in Class 12 Informatics Practices, explained in plain words, with games and quizzes to practise.
Kinds of Computer Networks
Part of: Networks and Their Devices
A network links two or more devices so they can share data and resources. A LAN covers one campus up to about 1 km at up to 1000 Mbps, a MAN spans a city like cable TV networks, and a WAN like the Internet stretches across countries.
Why it matters. Choosing the right network saves money and matches speed to distance. A classroom needs a LAN while worldwide branches need a WAN.
Key words
- Network
- : Two or more devices linked to share data and resources.
- Node
- : Any device that can send, receive or store network data.
- LAN
- : A fast network covering one site up to about 1 km.
- WAN
- : A network spanning countries, like the Internet.
Try it in two minutes
- Link two phones with a hotspot to show a tiny network.
- Share one printer between them to show resource sharing.
- Compare classroom, city and worldwide setups by area.
- Break data into imaginary packets and pass them along.
Try at home. List every network at home and label each as room, city or worldwide scale.
Devices that Move Data
Part of: Networks and Their Devices
A modem swaps digital bits with line signals, a network card with its unique MAC address plugs a computer into wires, a repeater rebuilds fading signals, a hub shouts to all while a switch whispers to the destination, a router joins networks, and a gateway guards the exit to the Internet.
Why it matters. Every home router box bundles several of these jobs. Knowing who does what makes fixing slow or dead connections possible.
Key words
- Modem
- : Swaps digital bits with signals for the line.
- MAC address
- : The unique tag of a network card on a network.
- Switch
- : Sends each packet only to its destination device.
- Router
- : Joins networks and repackages packets for the next hop.
- Gateway
- : The gate through which a network reaches the outside world.
Try it in two minutes
- Whisper down a long line to show fading signals.
- Repeat the whisper loudly halfway to show a repeater.
- Shout a message to a room versus handing it to one person for hub versus switch.
- Sort letters by address to show routing.
Try at home. Find the home router box and list which jobs it bundles: modem, switch, router or access point.
Shapes of Networks
Part of: Shapes of Networks and Online Services
Topology is the layout of a network. Mesh links every pair and needs 10 wires for 5 devices, ring passes data one way round a circle, bus shares one backbone, star hangs every device off one central hub, and tree grafts basic layouts into branches.
Why it matters. Layout decides what breaks when. Star shrugs off one device failing but dies with its hub, while mesh survives any single break at high wiring cost.
Key words
- Topology
- : The arrangement of devices and links in a network.
- Mesh
- : Every device links directly to every other device.
- Ring
- : Each device links to two neighbours in a one-way circle.
- Star
- : Every device links to one central hub device.
- Tree
- : Branches of basic layouts joined into a hierarchy.
Try it in two minutes
- Tie five friends to each other with string to feel mesh cost.
- Pass a ball one way round a circle for ring flow.
- Pin all strings to one centre knot for star.
- Remove the centre knot and watch the star fall.
Try at home. Draw all five layouts for six devices and count the wires each needs.
Internet, Web and Everyday Services
Part of: Shapes of Networks and Online Services
The Internet is the global road system of linked computers, while the Web is the interlinked pages travelling on it. Addresses name the protocol, domain and path, and mail, chat and internet calls are everyday services riding on top.
Why it matters. Mixing up the net and the web causes real confusion while reporting problems. Addresses, mail copies and calls are daily skills.
Key words
- Internet
- : The global network of linked computing devices.
- Web
- : Interlinked pages and resources shared over the Internet.
- URL
- : A web address naming protocol, domain and path.
- Attachment
- : A file sent along with an email message.
- VoIP
- : Voice calls carried over the Internet.
Try it in two minutes
- Draw roads and houses to show net versus web.
- Read a web address aloud in three parts.
- Draft a mail with one visible and one hidden copy.
- Compare a phone call with an internet voice call.
Try at home. Split three web addresses into protocol, domain and path, and send a test mail with an attachment.
What your child will practise
- Devices that Move Data: Candy Quick Fire (Quick Fire)
- Internet, Web and Everyday Services: Desert Quick Fire (Quick Fire)
- Internet, Web and Everyday Services: Ocean Puzzle (Clue Puzzle)
- Kinds of Computer Networks: Space Quick Fire (Quick Fire)
- Shapes of Networks: Candy Puzzle (Clue Puzzle)
- Quiz: Devices that Move Data (8 questions)
- Quiz: Internet, Web and Everyday Services (8 questions)
- Quiz: Kinds of Computer Networks (8 questions)
- Quiz: Shapes of Networks (8 questions)