"VHF" (Very High Frequency) and "UHF" (Ultra High Frequency) define the frequency band in which the wireless system operates.

The VHF frequency band extends from 30 MHz to 300 MHz. VHF wireless systems typically operate between about 168 MHz and 220 MHz, although a few frequencies outside this range may be available for specialized applications.

The UHF frequency band extends from 300 MHz to 3000 MHZ (3 GHz). UHF wireless systems typically operate between about 450 MHz and 950 MHz, with most falling between about 524 MHZ and 806 MHz. Again, other frequencies may be available for specialized applications.

Technically speaking, neither frequency band is "better" than the other. However, UHF systems offer a few advantages over VHF systems. The VHF frequency band has been in use by the public for decades and is very cluttered, whereas the UHF band was previously only available for military use and has recently been opened for civilian purposes. The UHF band has much less traffic, which translates into better sound quality and less likelihood of interference. Consequently, manufacturers have developed their highest quality systems in the UHF band.

Also see our section on "Which Channel Should I choose".