The term Wi-Fi is often used as a synonym for wireless local area network (WLAN). Specifically the term "Wi-Fi" is a trademark of a trade association known as the Wi-Fi Alliance. From a technical perspective WLAN technology is defined by the Institute of Electrical and Electronics Engineers (IEEE).
In computer networking everything starts with the physical layer, which for many years was a copper wire. The physical layer was expanded to include anything that represent the wire, such as fiber optic cable, infrared or radio spectrum technology.
Wireless network refers to any type of computer network that is not connected by cables of any kind. While cell phone technology is often discussed as a form of wireless networking, it is not the same as the wireless local area network (WLAN) technology discussed here.
What is Wi-Fi?
The term Wi-Fi has often been used as a technical term to describe wireless networking. Wi-Fi is actually a trademark of the Wi-Fi Alliance, a global non-profit trade association formed in 1999 to promotes WLAN technology. Manufacturers may use the Wi-Fi trademark to brand products if they are certified by The Wi-Fi Alliance to conform to certain standards.
A common misconception is that Wi-Fi is an acronym of Wireless fidelity, it is not. The Wireless Ethernet Compatibility Alliance wanted a cooler name for the new technology as the IEEE 802.11b Alliance was not all that catchy. The marketing company Interbrand, known for creating brand names, was hired to create a brand name to market the new technology, and the name Wi-Fi was chosen. The term 'Wi-Fi' with the dash, is a trademark of the Wi-Fi Alliance.
IEEE 802.11 defines WLAN technology
The actual technical standards for wireless local area network (WLAN) computer communication are know as IEEE 802.11. IEEE refers to the Institute of Electrical and Electronics Engineers a non-profit professional association formed in 1963 by the merger of the Institute of Radio Engineers and the American Institute of Electrical Engineers.
IEEE 802 refers to a family of IEEE standards dealing with networks carrying variable size packets, which makes it different from cell phone based networks, 802.11 is a subset of the family specific to WLAN technology. Victor "Vic" Hayes was the first chair of the IEEE 802.11 group which finalized the wireless standard in 1997.
This link takes you to the 802.11 specification that contains all the geek speak on how it works. --> IEEE-SA -IEEE Get 802 Program
How fast is Wi-Fi?
Wi-Fi speed is rated according to maximum theoretical network bandwidth defined in the IEEE 802.11 standards.
IEEE 802.11b - up to 11 Mbps
IEEE 802.11a - up to 54 Mbps
IEEE 802.11n - up to 300 Mbps
IEEE 802.11ac - up to 1 Gbps
IEEE 802.11ad - up to 7 Gbps
If you look at the IEEE 802.11 Wireless LANs standards you will see the ongoing evolution with several standards under development at this time to increase speeds even more.
Keep in mind that WiFi speed is how fast your internal network is, as in wireless LANs (Local Area Network)
Fast WiFi does not mean fast internet connection, it has nothing to do with the speed or bandwidth of you internet access.
How does Wi-Fi work?
A Wi-Fi enabled device such as a personal computer or video game console can connect to the Internet when within range of a device such as a wireless router connected to the Internet. wireless local area network (WLAN) technology allows your device to connect to the router, which in turn connects you to the internet. In order to connect to the internet, you need a unique IP (internet protocol) address. On your home network, when your router is connected to the internet, it has a public address, that is the one that faces the internet, and is unique in relationship of other routers on the internet.
Your router also has a local IP Address of something like 192.168.1.2 and this is a private IP address space. Addresses beginning with 192.168 cannot be transmitted onto the public Internet and are typically used for home local area networks (LANs). If you have four home computers, your router creates a home network and the four home computers have a unique number in relationship to each other. Your local computers connect to the router, either by a wire plugged into the router, or through a wireless signal.
Routers are used to create logical borders between networks, and in this allow a gateway, such as an access point to the internet to be shared. In geek speak terms subnetting can be very complex, but what is happening here is the process know as subnetting.