WiFi 802.11n, also known as WiFi-4, is a wireless networking standard introduced in 2009. It offers significant speed and range improvements over previous standards, with maximum theoretical speeds of up to 600 Mbps. 802.11n uses multiple transmit and receive antennas for improved performance and operates at 2.4 GHz or 5 GHz. This standard is popular due to its compatibility with many devices and is still common in many home and business networks.