A wireless LAN (WLAN) specification under development by the IEEE (Institute of Electrical and Electronics Engineers) that will serve as the successor to the 802.11ac specification, which is also currently under development. The 802.11ad standard is expected to be approved by the IEEE in 2014.
The 802.11ad specification operates in the 60GHz frequency band, as opposed to earlier 802.11 specifications such as 802.11ac, which operates in the 5 GHz range, and 802.11n, which operates in both the 5 GHz and 2.4 GHz ranges. It is also designed to offer much higher transfer rates than previous 802.11 specs, with a theoretical maximum transfer rate of up to 7Gbps (Gigabits per second).
See 802.11 for a complete overview of the 802.11x family of specifications.
Also see the "Wireless LAN Standards chart" in the Quick Reference section of Webopedia.
See also "How Wireless Networks Work" in the Did You Know... section of Webopedia.