3.2 understand the difference between longitudinal and transverse waves and describe experiments to show longitudinal and transverse waves in, for example, ropes, springs and water

Transverse
Vibrations (osculations) go up and down along the line of travel,
Light and electromagnetic waves travel in this way,
If you drop something in water the waves move up and down as they travel outwards,
If you lie a piece of string on a table and move one end up and down, the movement will pass through the object to the other end.

Longitudinal
The vibrations are in the same direction as the line of travel,
Sound waves travel in this way,
Compressions are where vibrations are close together, rarefactions are where they are more spread out,
If you push one end of a stretched spring the compression will move down the spring.

Watch these animations to see how the examples work: http://www.bbc.co.uk/schools/gcsebitesize/science/aqa/waves/generalwavesrev2.shtml