What is Wi-Fi? - Baidu Knows

Wi-Fi is a technology that can connect terminals such as personal computers and handheld devices (such as PDAs, mobile phones) wirelessly. The term Wi-Fi was coined by the Wi-Fi industry association (Wi-Fi Alliance). The emergence of Wi-Fi was the result of the 1985 decision by the U.S. Federal Communications Commission (FCC) to open up several wireless bands that could be used without government licenses. These so-called "junk bands" had been allocated to devices like microwave ovens that use radio waves to heat food. To operate within these bands, devices needed to use "spread spectrum" technology. This technology extends the radio signal across a wide range of frequencies, making the signal less susceptible to interference and harder to intercept.