Radio signals travel as waves, and waves come in different lengths. A waveband is a stretch of those lengths grouped together and used for one purpose — a band, like a band of colour, cut out of the whole range. The word belongs mostly to radio. On an old radio set you would see the wavebands printed on the dial and switch between them: long wave, medium wave, short wave, FM. Each is a waveband, holding many stations. So "stations on the same waveband" means stations you find in the same part of the dial, and you had to be on the right waveband before you could find a station at all. Because of that, the word gained a everyday picture-use about people. "We're on the same waveband" means we understand each other, we think alike — as if two radios tuned to the same place. Careful: the far commoner way to say this is "on the same wavelength". Both are heard, but wavelength is what most people say. Waveband now sounds slightly old, because young people meet radio through apps and choose stations by name, not by turning a dial. Engineers and officials still use it, and the near-synonym "band" is what you see on modern equipment: the 2.4 GHz band on your wifi router is the same idea.

波段（無線電波長的一段區間，如長波、中波、短波）