What is the [volume based on Ask (Bid)]?

[MaxNT]

Hello,

when I make new chart (menu File/New/Chart), in the field "Price based on" I can select Ask, Bid or Last (picture 1).
If I select "Ask" in this field, then what means the Volume on the chart (picture 2) ?
Is this the [total volume of all orders for sell] ?
Or it is the [volume of the best orders for sell (orders with the lowest price)] ?
Or something else ?

Thanks

[NinjaTrader_ChristopherS]

Hello MaxNT

Who are you connected to?

[MaxNT]

Who are you connected to?

Hello,
my provider is "NinjaTrader Continuum".

[NinjaTrader_ChristopherS]

Hello MaxNt

This will be the cumulative number of contracts at the bid and at the ask for the interval being charted