Wi-Fi

Wi-Fi is a way for computers, phones, and other devices to connect to the internet without using wires. It uses radio waves to send and receive information through the air. Wi-Fi works over short distances, usually inside a home, school, or coffee shop. It became common in homes in the early 2000s, and today billions of devices use it every day.

Wi-Fi works because of a small box called a router. The router plugs into the internet through a cable. It then sends out radio waves in every direction, like a small radio station. Your phone or laptop has a tiny radio inside it too. When the radio in your device picks up the signal from the router, the two can swap information back and forth. That is how a video, a game, or a website reaches your screen.

The radio waves Wi-Fi uses are not the same as the ones that carry music to a car radio. Wi-Fi waves are much shorter and carry much more information per second. They are a kind of light, actually, just at a color your eyes cannot see. The waves travel at the speed of light, which is about 186,000 miles per second. That is why a webpage seems to load the moment you tap a link.

Wi-Fi signals do not travel very far. Most home routers reach about 100 feet indoors. Walls, floors, and even fish tanks can block the signal or make it weaker. Metal blocks it the most. That is why the signal often gets weaker in the basement or in a room far from the router.

Wi-Fi was invented in the 1990s. A team of Australian scientists led by John O'Sullivan figured out how to send data through the air without losing it to echoes bouncing off walls. The first version of Wi-Fi for home use came out in 1997. It was slow by today's standards. A modern Wi-Fi connection can be hundreds of times faster.

Wi-Fi has changed how people live. Before it, getting online meant plugging a cable into a computer that stayed in one spot. Now you can watch a movie in the kitchen, video call a grandparent from the backyard, or do homework on the couch. Most public libraries, airports, and restaurants offer free Wi-Fi. Some cities are even trying to cover whole neighborhoods so anyone can connect outdoors.