In physics, wavelength's the distance between repeating units of a waveform. It's commonly designated by the Greek letter lambda (λ). Examples of wave-like phenomena are light, water waves, and sound waves. Waves may have arbitrary shapes, but recur periodically in time or space or both. A wave that doesn't move in space but oscillates in time's called a standing wave. Assuming the speed of the wave's fixed, wavelength's inversely proportional to frequency: waves with higher frequencies… (More on Wavelength)