A Wi-Fi channel is the means by which devices on wireless networks can send and receive data.
Currently, there are three bands available in the US: the 2.4 GHz, 5 GHz, and 6 GHz bands.
The 2.4 GHz band has 3 non-overlapping 20MHz bandwidth channels and one 40MHz channel. Where channels don't overlap, there is no interference. The 2.4 GHz band is ideal for sending moderate amounts of data over long distances.
The 5 GHz band has 25 non-overlapping 20MHz channels, 12 40MHz channels, six 80MHz channels, and two 160MHz channels. Wi-Fi 5 devices only use the 5 GHz band. Wi-Fi 6 devices are capable of using the 2.4 and 5 GHz bands. The 5 GHz band is capable of delivering and receiving exponentially higher amounts of data but over shorter distances than 2.4 GHz.
The 6 GHz band is the newest band to be opened up by the FCC back in April 2020. It has 59 non-overlapping 20 MHz channels, 29 40MHz channels, 14 80MHz channels, and 7 160MHz channels. The sheer spectrum of 1,200MHz of bandwidth will spur innovations in virtual reality, IoT, robotics, smart city Wi-Fi and other applications that produce billions of gigabytes of data.