Key Stage 2 computing · Networks and the internet

KS2 computer networks and the internet: a guide for parents

A computer network is a group of devices joined together so they can share information. In Key Stage 2, children learn what networks are made of, how the internet connects millions of networks around the world, and how data travels between devices. The aim is for children to understand that the internet is a real, physical system and not a vague cloud.

Computer networks and the internet, explained

A network can be as small as two tablets sharing a file or as large as the whole internet. Each device on a network is connected by a cable, by radio signals (Wi-Fi) or by a mobile connection. At school, children are likely to see a local network joining the classroom computers, a printer and a school server, where files are stored and shared. At home, a router connects phones, laptops, televisions and games consoles to each other and to the wider internet.

The internet is a network of networks. Home and school networks connect through internet service providers to much bigger networks, which are joined by high-speed cables laid across the country and under the sea, as well as by satellites and mobile masts. Websites and apps keep their data on servers, which are powerful computers that are always switched on and ready to send things on request. The device asking for information is sometimes called a client.

Data does not travel as one big lump. It is split into small chunks called packets, each labelled with where it came from and where it is going. Packets can take different routes across the network and are put back together in the right order at the other end. Children can model this by cutting a message into pieces and passing them along different chains of people. Not every school goes into this much detail, and it is a typical choice rather than a requirement, but it helps children see how a large video can arrive in seconds.

The internet carries many different services. The World Wide Web is one of them, alongside email, video calls, online games and file sharing. Children think about the opportunities these give for communication and collaboration: sending messages, working on the same file together, playing with other people and looking up information. Networks bring risks as well as benefits, and the curriculum asks children to use technology safely and responsibly, so lessons about networks usually include why passwords matter and why not everyone should have access to every file.

Words your child will hear

Network: Two or more devices connected so that they can share information.
Internet: A huge worldwide network of networks, joined by cables, radio links and satellites.
Router: A device that directs data between a home or school network and the internet.
Server: A computer that stores information and sends it to other devices when they ask.
Wi-Fi: A way of connecting devices to a network using radio signals instead of cables.
Packet: A small chunk of data labelled with where it is from and where it is going.
Internet service provider: A company that gives homes and schools a connection to the internet.

What the National Curriculum says

The programme of study for Key Stage 2 says:

Pupils should be taught to understand computer networks, including the internet; how they can provide multiple services, such as the World Wide Web, and the opportunities they offer for communication and collaboration
Aim: pupils can understand and apply the fundamental principles and concepts of computer science, including abstraction, logic, algorithms and data representation.

Objectives from the National Curriculum in England, © Crown copyright, used under the Open Government Licence v3.0.

A worked example: how a message reaches a friend

A child sends a short message and a photo from a tablet at home to a friend’s laptop in another town. Explain what happens on the way.

The tablet connects to the home router using Wi-Fi. The router is the doorway between the home network and the internet.
The tablet splits the message and the photo into packets. Each packet is labelled with the address it is going to, the address it came from, and a number that shows its place in the sequence.
The router passes the packets to the internet service provider through a cable. From there they travel across larger networks, from one connection point to the next, and each point sends them on towards their destination. Different packets may take different routes.
```
tablet, router, provider,
larger networks, friend’s provider,
friend’s router, friend’s laptop
```
The friend’s router receives the packets and sends them to the laptop. The laptop uses the numbers to put the packets back in the right order, and the message and photo appear.
If a packet goes missing on the way, the computers notice that it has not arrived and it is sent again, so the message arrives complete.

The message is split into labelled packets, sent through the router and across connected networks by different routes, then put back in order at the other end.

Common mistakes and how to help

“Wi-Fi is the internet”

Devices show a Wi-Fi symbol when they have an internet connection, so children treat the two as the same thing.

What helps: Explain that Wi-Fi only links a device to the router. A device can be on Wi-Fi with no internet if the router’s connection to the wider network is down. If your internet ever stops working, point out that the Wi-Fi symbol may still be showing.

“Wireless means there are no wires”

Phones and tablets feel cable-free, so the last few metres of the journey become the whole story.

What helps: Look at the back of a router, then talk about the cables in the street and under the sea. Nearly all internet traffic travels through cables for most of the journey.

“The cloud” is a mysterious place in the sky

The word is a figure of speech, and it makes stored data sound weightless.

What helps: Say that “the cloud” means files kept on servers in buildings full of computers, reached over the internet. Someone owns and powers those computers.

Thinking the internet belongs to one company or sits in one place

Children use the same few apps every day and assume they are the internet.

What helps: Describe it as many networks owned by lots of different organisations that agree to pass data to each other, like roads joined up between different towns.

How to help at home

Find your router. Look at the router with your child. Notice which devices connect by cable and which by Wi-Fi. Ask what would happen to the tablet if the router were unplugged. Don’t change any settings or passwords.
Act out packets. Write a short message in four or five pieces on separate pieces of paper, number each piece and shuffle them. Pass them to a family member across the room by different routes, then ask them to put the message back in order.
Trace a journey. Pick something your child does online, such as watching a video, and ask where the information is stored and how it gets to the screen. Draw the route with boxes and arrows: device, router, provider, server.
Talk about who can see what. Ask your child why the school network needs logins, and why home Wi-Fi has a password. Connecting devices is useful, but it also means choosing who gets to join the network.