What is Wi-Fi?

Wi-Fi is a way for devices to send internet data through radio waves instead of cables. Your router sends coded signals through the air, and your phone, tablet, or computer listens, replies, and trades tiny pieces of information very quickly.

Those signals are real even though your body cannot sense them. They can pass through many walls, but thick brick, concrete, and metal can weaken or bounce them, which is why a video may load well in one room and stall in another.