Wi-Fi is a trademark of the Wi-Fi Alliance, founded in 1999 as WECA (Wireless Ethernet Compatibility Alliance). The name of a popular wireless networking technology that uses radio waves to provide wireless high-speed Internet and network connections. The Wi-Fi Alliance, the organization that owns the Wi-Fi (registered trademark) term specifically defines Wi-Fi as any "wireless local area network (WLAN) products that are based on the Institute of Electrical and Electronics Engineers' (IEEE) 802.11 standards."
The purpose of Wi-Fi is to provide inter-operable wireless access between devices. Wi-Fi generally makes access to information between devices from many different manufacturers easier, as it can eliminate some of the physical restraints of wiring which can be especially true for mobile devices. A Wi-Fi enabled device such as a PC, game console, mobile phone, MP3 player or PDA can connect to the Internet when within range of a wireless network connected to the Internet.
Wifi networks can either be "open", such that anyone can use them, or "closed", in which case a password is needed. An area blanketed in wireless access is often called a wireless hotspot.
Wi-Fi networks have limited range. A typical Wi-Fi home router using 802.11b or 802.11g with a stock antenna might have a range of 32 m (120 ft) indoors and 95 m (300 ft) outdoors. Range also varies with frequency band. Wi-Fi in the 2.4 GHz frequency block has slightly better range than Wi-Fi in the 5 GHz frequency block. Outdoor range with improved (directional) antennas can be several kilometres or more with line-of-sight.
The most common wireless encryption standard, Wired Equivalent Privacy or WEP, has been shown to be easily breakable even when correctly configured. Wi-Fi Protected Access (WPA and WPA2), which began shipping in 2003, aims to solve this problem and is now available on most products. Wi-Fi Access Points typically default to an "open" (encryption-free) mode. Novice users benefit from a zero-configuration device that works out of the box, but this default is without any wireless security enabled, providing open wireless access to their LAN. To turn security on requires the user to configure the device, usually via a software graphical user interface (GUI). Wi-Fi networks that are open (unencrypted) can be monitored and used to read and copy data (including personal information) transmitted over the network, unless another security method is used to secure the data, such as a VPN or a secure web page.
Sometimes you would see there are public computers set up at hotspot for you to access Internet, but be alerted that key-loggers may be installed to capture all your keystrokes.
The other issue is your browsing history would be cached and others who use it later would know the site you visited. The worst case is you leave the login credential on the computer after saving it in login page.
