And what the difference between waves and pulses?

[physics user1]

In images I always seen pulses as a part of a wave corresponding to an half of a piece of wave, but it is called still a pulse when we have a part with a complete wavelength? I mean this (in the photo)

And what the difference between waves and pulses?

What I think is that is still a pulse because a wave is a non stoping oscillation, not just one

 

[blue_leaf77]

A pulse is a form of wave. In particular, it's called pulse, usually because it has finite extent in space and time - it's oscillating and propagating, but confined within certain spatial extent at any given time. So, in this regard, both situations you drew there describe two different pulses. You can build a pulsed wave by superposing many sinusoidal waves of different frequencies. For example, try plotting $\sum_{k=1}^10 \sin k\omega x$, you should see that this function takes the form a repeated pulses which also oscillates along.

 

[FactChecker]

I would call the first one a doublet and the second one a pulse. The difference from a wave is the abrupt start and stop that implies a very complicated frequency content. Usually the doublet and the pulse are in the form of steps, but I would still guess that the frequency content of your examples are closer to the doublet / pulse than to a continuous wave.