What is the difference between particle velocity and wave velocity of a simple harmonic progressive wave?

Question

I encountered these words regarding reflection of simple harmonic progressive wave. 
In detail, it was written,
"...Consider a crest of a transverse wave of a string incident normally on on a wall. As crest cannot travel further, wave velocity is reversed. Now, the particle of the wall at which the crest is incident is not free to vibrate. Therefore, reflection takes place in such a way that the particle velocity is also reversed. Reversal of particle velocity causes a change of phase of pi rad. Hence, crest is reflected as trough..."
Such explanations are given regarding troughs, and also longitudinal waves.

Are these velocities i.e. particle velocity and wave velocity, different from each other?
What are they actually?

Please explain.

Thank you!

Ajinkya N · Accepted Answer

Consider a string tied at one end and you are moving the other end in your hand. If you carefully observe, the wave is traveling through the rope to the tied end. But, the particles, which constitute the rope move only in up and down direction. They do not move parallel to the rope at all. If that was the case, after a bit of time, you would have had a rope that was denser on the tied end. So particle velocity is perpendicular to the wave velocity in a transverse wave. It is equal to (omega) squared times the wave velocity.

? · Answer

The frequency is going to be how high/low the wave goes The velocity is going to be how thick/thin the curves of the wave are

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What is the difference between particle velocity and wave velocity of a simple harmonic progressive wave?

2 Answers