Q:

Can't understand concept, range of the pulse (waveform)

I am working on the lab which is allowed to ask other people for hints.

In the image, program called "Audacity" is used to capture that waveform.
Question 1

In the image it says, "The peak-to-peak span of the signal is about 2.0 V"

It says its span range is 2.0 V, but I think that it spans from around -0.2 (lowest point in the wavefore picture) to +0.8 (highest point in the wavefore picture) according to picture. But why this description says it is 2.0 V?
Question 2

In the image it says, "the graph below can show a range of about 4 volts top-to-bottom"

Similarly, I think total range of top-to-bottom in the image is from -1.0 to +1.0, which I think 2V in total. But why this description says it is 4 volts?

A:

The Y axis in Audacity's graph is scaled in units, where +/- 1.0 is the full scale range of the DAC or ADC.
In your link, where it says 'the graph below can show a range of about 4 volts top-to-bottom', you are being told what the graph's scale means in terms of real world volts. This obviously depends on what amplifiers or attenuators are connected externally.

