5 GHz band
5 GHz bandThe frequency range from 5.15 GHz to 5.85 GHz, which is unlicensed and used for many communications applications, including Wi-Fi and cordless phones. Commonly designated as "5G," after the turn of the century, 5G became widespread after version 802.11a debuted. The 5 GHz band is also used in the subsequent 11n, 11ac and 11ax versions of Wi-Fi. See 5G, 802.11 versions and ISM band.
2.4 GHz and 5 GHz
One often sees 2.4 GHz and 5 GHz (2.4G and 5G) written together because they refer to the two common Wi-Fi frequency bands. The reason 5 GHz is expressed as a whole number but 2.4 GHz has the dot-4 is because the 5 GHz band covers a range from 5.15 GHz to 5.85 GHz, and it is shortened for simplicity to 5 GHz. However, the 2.4 GHz range is entirely within 2.4 GHz (see 2.4 GHz band).