What are the differences between primary and secondary and seismic waves?

Firstly, there are 3 types of seismic waves. Long Waves, Primary Waves(Longitudinal) and Secondary Waves(Transverse). Long Waves travel quickly along the Earth's crust, the thin outer layer. Primary Waves are longitudinal waves, they can travel both through solids andliquids, so they travel through the crust, the mantle, and the outer core (note that they refract through each layer, as each layer has a different density. Secondary Waves are transverse waves, they can only travel through solids, so they go through the inner and outer mantles, and curve away from the cores.