There are two main types of wave: Transverse Waves and Longitudinal Waves. Below is some information and examples of both:

Transverse waves:
A transverse wave moves across the direction in which the wave is travelling.
An example of a transverse wave is the sea - imagine the shape of a wave.
Another good example is a light wave.

Longitudinal waves:
Longitudinal waves look like this: ||| | | || || | |||| | | | ||
They have a series of compressions and rarefractions.
A compression is when the wavelength (distance between each wave) is small.
A rarefraction is when the wavelength is large.
Longitudinal waves pass on energy as a series of vibrations.
These are sound waves.

Wavelength. The wavelength is the length of a wave e.g. the distance between one crest (high part) and the next crest.

Frequency. Measure of how many waves pass in one second.

Amplitude. The distance between the crest of the wave and the centre line.

Formulae. There are two main formulae on the topic of waves:
Velocity (m/s) = frequency (Hz) x wavelength (m)

Speed (m/s) = distance (m) / time (s)

Click here for coursework essays on waves