Volume at bottom of chart displays trades for given period (candle) while Volume Profile displays at what price most action has taken place. It is totally different than Traded volumes. Just do a google search you will get all the needed information.
It is nothing different. As I said in first reply to you, it is the same. Volume displayed on x axis and volume displayed on volume profile are not different. It is the same volume count, depicted in a different format.
you see, different types of charts like candle stick, Bar charts, Point n figures etc... where the same price data is presented in different formats, the same way, volume profile is another format of showing same volume data in a different way.
once you understand its logic, there is no use of volume profile, as you can visualize its output from normal volume on x axis.