Wi-Fi is a family of wireless networking technologies based primarily on the IEEE 802.11 standards and used to connect computers, smartphones, tablets, televisions, printers, access points, cameras and other devices to local networks using radio communication. The Wi-Fi name is a certification and branding term associated with the Wi-Fi Alliance, while IEEE 802.11 defines the underlying technical standards. Wi-Fi normally operates using radio frequencies in bands including 2.4 GHz, 5 GHz and, for newer generations, 6 GHz.
It allows devices to communicate without a physical Ethernet cable and is one of the principal methods through which consumer devices access local networks and the Internet. Wi-Fi is not itself the Internet. It is a wireless local-area networking technology that can provide a path to a router, access point or other network infrastructure, which may in turn provide connectivity to wider networks.
Wi-Fi networks generally use access points that provide wireless connectivity to client devices. A home router often combines an access point, Ethernet switch and IP router in one physical appliance. The access point broadcasts network information and allows compatible clients to associate with it. Once connected, a device can communicate with other devices on the local network and, when appropriate routing and Internet service are available, reach external networks.
Wireless frames use mechanisms defined by IEEE 802.11, while higher-level protocols such as IP, TCP and UDP can operate over the resulting link. Modern Wi-Fi systems use sophisticated modulation, coding, channel management and multiple-antenna techniques to increase throughput and reliability. The actual speed experienced by a user depends on the negotiated physical link rate, signal conditions, channel width, interference, protocol overhead, access-point capabilities and traffic from other devices.
Wi-Fi has developed through generations that are commonly marketed using names such as Wi-Fi 4, Wi-Fi 5, Wi-Fi 6, Wi-Fi 6E and Wi-Fi 7. These correspond broadly to successive IEEE 802.11 amendments, including 802.11n, 802.11ac, 802.11ax and 802.11be. Wi-Fi 4 introduced or popularised technologies such as multiple-input multiple-output, commonly called MIMO, and operation across multiple frequency bands. Wi-Fi 5 focused heavily on higher throughput through 5 GHz operation and wider channels.
Wi-Fi 6 introduced technologies such as Orthogonal Frequency Division Multiple Access, or OFDMA, improved multi-user operation and Target Wake Time. Wi-Fi 6E extends Wi-Fi 6 operation into the 6 GHz band where permitted. Wi-Fi 7 introduces further improvements including wider channels, Multi-Link Operation and higher-order modulation. Generation names simplify marketing but do not eliminate the need to examine the actual router, client and regional spectrum capabilities.
Wi-Fi performance depends heavily on radio propagation. Walls, floors, furniture, metal structures and other obstacles can weaken signals, while neighbouring wireless networks and other radio devices can create interference. The 2.4 GHz band generally provides better propagation through obstacles and greater range than higher-frequency bands, but it has fewer channels and can be heavily congested.
5 GHz generally provides more spectrum and can support higher performance under suitable conditions, while 6 GHz provides additional spectrum for compatible newer devices but has different propagation characteristics and regulatory restrictions. Wider channels can increase theoretical throughput but consume more spectrum and may be more vulnerable to congestion or unavailable in a crowded environment. Multiple antennas allow technologies such as spatial multiplexing and beamforming to improve capacity or reliability. These factors mean that a router's advertised maximum speed is not equivalent to the speed a user will necessarily obtain.
Wi-Fi security has evolved considerably. Early wireless security methods such as Wired Equivalent Privacy were found to have serious weaknesses and are obsolete. WPA and WPA2 introduced stronger protection, while WPA3 provides newer authentication and encryption mechanisms. A modern secured home network generally uses a strong passphrase or an appropriate enterprise authentication system. Wi-Fi security involves both authentication and encryption, preventing unauthorised devices from simply joining the network and helping protect traffic transmitted over the radio link.
Enterprise Wi-Fi can integrate with authentication servers and individual user credentials, while public Wi-Fi may use captive portals or other access mechanisms. Even encrypted Wi-Fi should not be treated as a complete security boundary because application-level encryption such as HTTPS remains important when communicating across networks.
Wi-Fi can operate in several network configurations. Infrastructure mode uses access points and is the standard arrangement in homes and businesses. Ad hoc or peer-to-peer approaches have existed for direct device communication, while technologies such as Wi-Fi Direct allow compatible devices to establish direct wireless connections for specific applications. Mesh Wi-Fi systems use multiple coordinated access points or nodes to provide broader coverage across a building.
A mesh system may use wireless or wired backhaul to connect its nodes, with wired backhaul often providing more predictable capacity because client traffic does not have to share the same radio path with inter-node communication. Enterprise deployments can use numerous coordinated access points, centralised management, roaming support and radio-frequency optimisation. The architecture therefore varies considerably between a simple home network and a large institutional wireless environment.
Wi-Fi originated from the broader development of IEEE 802.11 wireless local-area networking standards during the 1990s. The first 802.11 standard was published in 1997, although its early performance was limited compared with later generations. The Wi-Fi Alliance helped promote interoperability and consumer adoption by certifying products against relevant standards. The technology became increasingly widespread as laptops, smartphones and broadband Internet access expanded. Successive IEEE amendments increased throughput, improved reliability and made wireless networks more efficient when serving many devices simultaneously. Wi-Fi has consequently evolved from a relatively low-speed alternative to wired networking into a sophisticated high-bandwidth access technology used in homes, offices, public spaces, industrial environments and increasingly dense networks containing large numbers of connected devices.
Wi-Fi is not inherently equivalent to wireless Internet access. A device can be connected to a Wi-Fi network even when the Internet connection behind that network is unavailable. Wi-Fi also differs from Bluetooth, which generally targets personal-area peripheral communication and lower-power operation. Wi-Fi typically provides substantially greater network capacity and integrates naturally with IP networking, whereas Bluetooth uses application-specific profiles and is optimised for different workloads. Another misconception is that a high-speed Internet subscription guarantees the same speed over Wi-Fi. The wireless link between the device and access point can become the limiting factor independently of the Internet connection. Wi-Fi performance is determined by the complete radio environment, equipment capabilities, configuration and network architecture rather than by the broadband speed alone.
