The IEEE802.11x Family

This article lists the most common IEEE802.11x standards for your convenience:

802.11 Defines wireless transmission at 1 Mbps or 2 using the 2.4 GHz frequency spectrum
802.11a Provides a bandwith of up to 54 Mbps on 5 GHz
802.11b Also known as Wi-Fi or 802.11 high rate provides bandwiths of up to 11 Mbps in the 2.4 GHz frequency spectrum
802.11g Provides bandwiths of up to 54 MPbs on 2.4Ghz
802.11i Often reffered to as WPA2. Has some security enhancements with particular focus on authentication
802.11n Can operate in 2.4 and 5 GHz. Can reach speeds of up to 600 Mbps