a. Pulse Wave is a kind of non-sinusoidal waveform that is similar to a square wave, but does not have the symmetrical shape associated with a perfect square wave.
b. Periodic wave is a periodic function of one-dimensional space that moves with constant speed.
c. Transverse wave is a moving wave that consists of oscillations occurring perpendicular (right angled) to the direction of energy transfer.
d. Longitudinal waves are waves in which the displacement of the medium is in the same direction as, or the opposite direction to, the direction of propagation of the wave.