WiFi is a form of wireless internet access (Wireless Local Area Network). WiFi is different from cellular internet access in that it is delivered via hotspots and is limited to specific areas, like hotels, hospitals, restaurants, airports, airplanes, ships, libraries, schools and universities, stores, shopping malls, and apartment complexes. To access WiFi, one must have a device capable of reviving and sending the signals, like a laptop, mobile phone, or portable gaming device. DSL and cable connections are typically used to provide internet connectivity to WiFi access points, which in turn provide Internet access to wireless users. WiFi can also be provided in a residential setting using a wireless router or internet gateway device. Wi-fi was invented by the Australian government's research arm, the CSIRO.
In some places such as Sunnyvale in Silicon Valley, WiFi is largely replaced by WiMAX, which can service entire cities.