The Wave reference article from the Simple Wikipedia on 24-Jul-2004
(provided by Fixed Reference: snapshots of Wikipedia from wikipedia.org)

Wave

Helping orphans the way you would do it
A wave is a way to transfer energy, such as light and sound, from one point to another without any particle of the medium being permanently displaced. It does not have a travel of matter from a source to a receiver.

There are two types of waves in terms of the methods of vibration:

Transverse wave: the vibrations of particles are perpendicular to the direction of travel of wave.

Longitudinal wave: the vibrations of particles are parallel to the direction of travel of wave.

         

This article is a stub. You can help Wikipedia by adding to it.