The Volume simply displays the number of shares traded during a time period. It is simple but is also one of the most important indicators. 

The Volume helps to determine the strength of the price moves. 

Inputs:

Zero_Based = On/Off (Valid only in MyChart.)

If you want the volume bars to be scaled with a base of zero this parameter should be "On", otherwise the volume is scaled using the lowest volume bar as a base.

Indicator Type: Market Strength