What does a wavefront represent?

A wavefront represents a surface over which an arbitrary wave has a constant phase. In simple terms, it consists of all points that are oscillating in unison at a particular moment in time. This means that if you were to visualize a wavefront, it would be a line or surface where every point along it experiences the same displacement and phase of vibration.

For example, in a water wave, the crest of the wave can be viewed as a wavefront; each part of the crest is at the same height above the still water. Thus, when we refer to wavefronts in the context of waves, we are specifically talking about the collection of points that are all vibrating in the same phase of the wave cycle.

While amplitude, wavelength, and frequency are important characteristics of waves, they describe other aspects of the wave. Amplitude indicates the maximum displacement of points on the wave, wavelength is the distance between successive wavefronts, and frequency refers to how many cycles of the wave occur in a given time period. None of these directly define the concept of a wavefront itself.