A frequency band (or frequency range or radio frequency band) is a range of wave frequencies. It most often refers to either a range of frequencies in sound or a range of frequencies in electromagnetic radiation, which includes light and radio waves.
A frequency band can be identified by the difference between its lower and upper limits, i.e. bandwidth, as well as by its actual lower and upper limits, e.g., a 10 MHz band in the 120 to 130 MHz range.
“Each frequency band has both advantages and disadvantages. At low frequencies the signal propagates along the ground; attenuation is low but atmospheric noise levels are high. Low frequencies cannot carry enough information for video services. At higher frequencies there is less atmospheric noise but more attenuation, and a clear line of sight is needed between the transmitter and receiver because the signals cannot penetrate objects. These frequencies offer greater bandwidth, or channel capacity."