ELI5 Wi-Fi - What is it and how does it work?

WiFi is a way for devices to talk to each other without wires. It uses invisible waves that travel through the air, kind of like sound, but much faster and silent. These waves are called radio waves. They are the same type of waves used by radios and walkie talkies.

At the center of most WiFi is a router. The router is the little box in your home with blinking lights. The router is connected to the internet using a cable from your internet company. Think of the router as a translator and traffic cop at the same time. When your phone, tablet, or computer wants to load a website, it first sends a message to the router. That message is turned into radio waves and sent through the air. The router hears those waves and understands them. Then the router sends the request through the cable to the wider internet.

The internet sends back the information. This could be a video, a picture, or text. The router receives it and turns it back into radio waves. Those waves travel through the air again and reach your device. Your device turns the waves back into data you can see on the screen. This all happens very fast, usually in less than a second. WiFi works best over short distances. Walls, floors, and large objects can weaken the signal. That is why WiFi is usually stronger when you are closer to the router. Things like microwaves, baby monitors, and other WiFi networks can also cause interference, which is like noise that makes it harder to hear the message.

WiFi uses rules so devices do not talk over each other. Each device takes turns sending and receiving data. The router helps manage this so everything stays organized. If many devices are connected at once, each one gets a smaller turn. That is why WiFi can feel slower when lots of people are online. WiFi networks are usually protected with a password. This keeps strangers from using your internet and from seeing your data. When you enter the password, your device and the router agree on a secret code. They use this code to scramble the messages so only approved devices can read them.

In simple terms, WiFi is just devices sending tiny messages through the air using radio waves. The router listens, replies, and passes messages to and from the internet. It feels like magic, but it is really just fast talking, good rules, and invisible waves doing their job.