What does vhf and uhf mean?

Very High Frequency and Ultra High Frequency. They are ranges of frequencies of radio waves in the electromagnetic spectrum. VHF ranges from about 30MHz to 300MHz, UHF is from about 300MHz to 3GHz. They are further subdivided into bands for; marine, amature, and other 2 way radio use, also designated channels for television and radio broadcast stations, as well as other uses throughout the world. In the US on the now defunkt analog television system VHF channels were 2-13 UHF channels were 14-83.