Waves are all around us in our every day lives and you use them all the time without even noticing.  Lots of things come in waves; such as light, sound, earthquakes and the sea.  However we will be looking at sound waves and how they are created.

The easiest type of wave to explain is called a Transverse Wave.  It sounds complicated but is easy to understand if you consider a mexican wave.

As a mexican wave moves along a row of people it travels left to right as shown below, however the people are not actually moving from left to right, only up and down.

You can use a piece of string to set up a standing wave between two people.   See Experiment 1.