a) Pulse Wave: A non-repeating single disturbance.

b) Periodic Wave: Regularly repeating disturbances, repeating intervals.

c) Transverse Wave: Wave is across, disturbance is at a right angle to the the direction the wave will travel.

d) Longitudinal Wave: Disturbance is in the same direction as the direction of travel, as springs are compressed the waves travel out lengthwise.