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| Wi-Fi Signal logo |
WHAT IS Wi-Fi?
Wi-Fi Wifi, is a mechanism for wirelessly connecting electronic devices. A device enabled with Wi-Fi, such as a personal computer, video game console, smartphone, tablet, or digital audio player, can connect to the Internet via a wireless network access point. An access point (or hotspot) has a range of about 20 meters (65 ft) indoors and a greater range outdoors. Multiple overlapping access points can cover large areas.
A Wi-Fi enabled device such as a PC, smartphone, tablet or games console, can connect to the Internet when within range of a hotspot. Hotspot coverage can comprise an area as small as a single room with wireless-opaque walls or as large as many square miles covered by overlapping access points. "Wi-Fi" is a trademark of the Wi-Fi Alliance and the brand name for products using the IEEE 802.11 family of standards. Wi-Fi products that complete Wi-Fi Allianceinteroperability certification testing successfully may use the "Wi-Fi CERTIFIED" designation and trademark.
Uses
To connect to a Wi-Fi LAN, a computer has to be equipped with a wireless network interface controller. The combination of computer and interface controller is called a station. All stations share a single radio frequency communication channel. Transmissions on this channel are received by all stations within range. The hardware does not signal the user that the transmission was delivered and is therefore called a best-effort delivery mechanism. A carrier wave is used to transmit the data in packets, referred to as "Ethernet frames". Each station is constantly tuned in on the radio frequency communication channel to pick up available transmissions.
Internet access 
USB wireless adapter
A Wi-Fi-enabled device can connect to the Internet when within range of a wireless network connected to the Internet. The coverage of one or more (interconnected) access points—called hotspots—comprises an area as small as a few rooms or as large as many square miles. Coverage in the larger area may depend on a group of access points with overlapping coverage. Outdoor public Wi-Fi technology has been used successfully in wireless mesh networks in London, UK.
Wi-Fi provides service in private homes, high street chains and independent businesses well as in public spaces at Wi-Fi hotspots set up either free-of-charge or commercially. Organizations andbusinesses, such as airports, hotels, and restaurants, often provide free-use hotspots to attract customers. Enthusiasts or authorities who wish to provide services or even to promote business in selected areas sometimes provide free Wi-Fi access.
Routers that incorporate a digital subscriber line modem or a cable modem and a Wi-Fi access point, often set up in homes and other buildings, provide Internet access and internetworking to all devices tuned into them, wirelessly or via cable. With the emergence of MiFi and WiBro (a portable Wi-Fi router) people can easily create their own Wi-Fi hotspots that connect to Internet via cellular networks. Now iPhone, Android, Bada and Symbian phones can create wireless connections.[1]
One can also connect Wi-Fi devices in ad-hoc mode for client-to-client connections without a router. Wi-Fi also connects places normally without network access, such as kitchens and garden sheds.
