Wavefronts are rays used in the graphical representation of wave behaviour. Wavefront is defined as the locus of all the points with a constant phase. A ray at any point on the wavefront is normal to the wavefront. The ray shows the direction of propagation of the wave. Ray extends outward from the source.
The shape of a wavefront depends on the source. A wavefront from a point source is spherical or circular, while an extended large source has a plane or flat wavefront.