What is Wi-Fi?
In one sentence: A way of joining the internet without a cable, using radio waves between a router and your devices, usually at 2.4 or 5 GHz.
A little more
Wi-Fi connects devices to your router using radio waves, usually at 2.4 or 5 GHz (and on newer kit, 6 GHz). The router turns internet data into radio signals and back again, many millions of times a second.
Signal fades with distance and with every wall, fridge or fish tank in the way. Metal and water are the worst; a wooden door barely matters.
It's a bit like… A walkie-talkie conversation between your phone and the router, just enormously faster.
See it in action
- 7Why does Wi-Fi get weaker through walls?Build a little house, drag the router around and watch the Wi-Fi signal spread room by room.7 min · interactive
- BonusHow does a photo fly to the phone next to you?Send a pretend photo to the phone next to you and watch how AirDrop and Quick Share really work: a tiny Bluetooth shout to find each other, a private Wi-Fi lane with no router, and numbered pieces that fly over like paper aeroplanes and click back together like a jigsaw.8 min · interactive
Do it for real
Free grown-up tools and guides on Tooltern, our sister site. They work in your browser and nothing is uploaded.