Wave is due to the disturbance of a medium as a result ,energy is transferred from one place to another through it. CLASSES OF WAVES1] Mechanical Waves2] Electromagntic Waves.1] MECHANICAL WAVES: These are waves that require or need a material medium for their propagation e.g water waves in ripple tank, sound waves.TYPES OF MECHANICAL WAVESA) TRANSVERSE WAVES: These are waves which travels perpendicularly to the direction of the propagation or vibration of the waves,e.g waves on plucked string.B] LONGITUDINAL WAVES: These are waves which travel along the same direction as that of the objects, e.g. Sound waves.C] STATIONARY/STANDING WAVES: These are waves due to interference of two waves travelling in opposite direction. For them to interfere, the must have the same frequency and amplitude e.g. Sinuosodal waves.2] ELECTROMAGNETIC WAVES: These are waves that do not need a material medium for their propagation, but the ravel successfull in free space (vacum). They travel with the speed of light in vacuum 3 x 10^8m/s.