Wavefront is the locus of all vibrating particles which are in the same phase. The shape of the wavefront is different according to nature and distance from the source of light.
In physics, the wavefront of a time-varying field is the set of all points where the wave has the same phase of the sinusoid. The term is generally meaningful only for fields that, at each point, vary sinusoidally in time with a single temporal frequency. Wavefronts usually move with time.