With Wi‑Fi, you can connect to the internet without using a cable. Your phone or computer shares information with a nearby router.
Wi‑Fi uses radio waves. These waves are invisible, but they can move through the air. The router sends small signals, and your device sends signals back.
When you open a web page, your device sends a signal asking for information. Then the router sends data from the internet to your device. Pictures and words are part of this data.
Walls and distance can make the signal weaker. That is why Wi‑Fi often works better when you are close to the router.