In physics a wave is a disturbance or oscillation that travels through spacetime, accompanied by a transfer of energy. Wave motion transfers energy from one point to another, often with no permanent displacement of the particles of the medium—that is, with little or no associated mass transport. They consist, instead, of oscillations or vibrations around almost fixed locations. Waves are described by a wave equation which sets out how the disturbance proceeds over time. The mathematical form of this equation varies depending on the type of wave. Plz. approve my answer by clicking Yes given below, if u loved it... Plz/.... AND BEST OF LUCK!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

The earliest wave to visualise is water wave , when you drop a stone inside a calm river ripples travel from the point where the stones are droped inside the water. 

The disturbance travels out from the center of the pattern, but the water does not travel with the wave. Mechanical waves—such as water waves, waves on a rope, waves in a spring, and sound waves—have two general characteristics:

• A disturbance is in some identifiable medium.

• Energy is transmitted from place to place, but the medium does not travel between two places. 

  For the sake of simplicity, idealized one-dimensional waves on a rope and two-dimensional water surface waves with no friction-like forces provide the wave model. For ease of analysis, a pulse that is a single short wave will be used to illustrate wave characteristics that also hold true for more complex waves. 

  Further there are two types of waves longitudinal and transeversal waves.
   

in which energy is transmitteed from one place to another without any displacing the particles of medium 

eg ball is moving and hit the wall and break it

here energy is transfered to wall by ball itself

consider example of persons standing in the row

last person pushes the second last person and second last to to make him stand erect he push the next one to balance himself similarily next to next and this energy moves throughout but persons are still there

The motion in which wave travels is called wavemotion.Generally it consists of "crests" and "troughs"....