What is volume-at-price "all bars?"

[Rusty3]

Hi,

Volume Source: Select the source that the study will use as the basis for the study: visible bars, current session bars, or all bars.

I understand "visible bars," and "current session," but what is "all bars?" How far back are we talking here?

Thanks,
Rusty A

[eostrom]

We are talking about how far back you have the chart populated. It's just as many bars as there are on the charts.