Dispersion refers to the phenomenon where waves, such as light or sound, spread out or disperse as they propagate through a medium. In optics, dispersion occurs when different wavelengths of light travel at different speeds through a material, causing the light to separate into its component colors, as seen in a prism splitting white light into a spectrum. This variation in speed or phase velocities for different wavelengths leads to the separation or spreading out of the waves. In the context of waves in a medium, dispersion can affect the overall waveform, altering its shape or causing distortion. Understanding dispersion is crucial in various fields, including optics, acoustics, and material science, as it impacts the behavior of waves in different mediums and underpins phenomena like chromatic aberration in lenses or the spreading of signals in fiber optic communication.