Wi-Fi is a wireless technology that uses radio waves to transmit data through the air as an alternative to wired networks. It works by translating digital data into radio signals using a wireless adapter, which are then transmitted to and decoded by a router. The key advantages of Wi-Fi are that it provides wireless networking without wires, allows for fast and easy deployment, and is secure and easy to manage. However, it also has limitations such as shorter range than wired connections, slower speeds, security risks from greater exposure, interference from other devices, and higher power consumption.