Ray goes along a straight line. Wavefront spreads equally in all directions.
Ray is always normal to the wavefront.
Based on ray concept the first law of reflection will be stated as:
The incident ray, the reflected ray and the normal all the three lie in the same plane.
But by wave front concept we have to state the same with an alteration
The incident wavefront, the reflected wavefront and the reflecting surface all the three are perpendicular to the same plane.