Networks and Wi-Fi: from home to the world

A house with a router sending out Wi-Fi waves, and a fiber cable leading out to the world

📖 In short

When you connect to the internet from home, a long journey begins: from your device to the router by invisible waves, then through a wire to the street, then through cables under the ground and the seas, until it reaches a server in another city or continent. And all of that happens in less than a second!

🤩 Did you know?

Light in optical fiber travels about two hundred thousand kilometers a second.
Weak signal? Try moving closer to the router or moving big metal things away from it.
Bluetooth uses radio waves too, but they only reach a short distance, like for earbuds.
Wi-Fi needs a password so strangers can't use it.

🔎 Find out more

🌟 Wi-Fi: invisible waves

Wi-Fi sends information by radio waves, just like a radio but faster. We can't see or hear them, but they fill the house. Thick walls weaken them, so the signal is weaker in faraway rooms.

🔍 The router: a traffic officer

The router connects all the devices at home to each other and to the internet. It knows every device's address and sends each message to the right one, so your brother's video doesn't end up on your phone by mistake.

💡 Optical fiber

Many cables today are glass threads thinner than a hair, where light travels very fast carrying information. This is “optical fiber”.

🎯 A network of networks

Your home is a small network, your school is a network, and many companies have networks. The internet is all these networks joined together, which is why its name means “between networks”.

🧭 Signal bars

The little bars in the corner of the screen tell you how strong the Wi-Fi signal is: the more bars, the stronger the signal and the faster the connection.

🌈 The phone network

Outside the home, a phone connects to big masts that each cover an area called a “cell”. When you move, the phone switches from one mast to another without the call dropping.

📊 See how it works

The devices at home connect to the router over Wi-Fi, and the router connects to the internet by optical fiber — From the devices at home to the router, then through optical fiber to the internet.

📚 Key words

Wi-Fi: A connection to the internet by radio waves
Router: The device that connects home devices to the internet
Optical fiber: Glass threads that carry light and information

🧪 Try it at home

Walk around the house with a phone or tablet and watch the Wi-Fi bars in each room. Draw a map of the house and color the rooms by signal strength. Where is the weakest spot? And why do you think that is?

🧩 Test yourself

1 How does Wi-Fi send information?

2 Which device sends messages to the right devices at home?