1. The correct term would be "Graphical representation of digital audio data".
1a. However, that's not "widely used". The most widely used industry term would be "waveform",
even though it isn't a waveform! This is because the early designers of graphical representations
of digital audio data decided to use a representation which resembled a waveform, so analogue
engineers would find it easier to relate to. You can easily see this, zoom right in and you will see
a series of steps, not a waveform (which is a continuous function that doesn't have any steps)!
2. Again, neither! Although "waveform" would be more common.
We've been through all this before!
What I described was the origin of the term in music production, many decades ago. However,
it's now quite often used for other purposes, as
@bigshot stated. Agreed
that it's use is therefore rather ambiguous but in practice it's not too bad, usually it's meaning is
obvious within the context of discussion or, we can simply ask for clarification if necessary.
G