VPOC is the Volume Point of Control (volume based)
POC is the Point of Control (time based)
The VPOC relates to volume and POC relates to time. Both represent where the most trading occurred. VPOC is where the most volume occurred for the specified session or time frame. POC is the price at which trading spent the most time at.
Very often people confuse time with volume and think that the price the market traded at the longest would have the most volume, but this is a misconception. Especially when looking at 24 hour charts, the POC does not necessary mean the highest volume price. If only viewing the day session, many times the POC and VPOC are very close or the same, but not always.
Which is more important? – That is up to you. Some traders prefer the VPOC because it is more exact when inferring how much interest a particular price was for traders, both buyers and sellers. If you use Market Profile, it often references the POC. Our software, MarketDelta, can use both the VPOC or POC when viewing a Market Profile chart.
If you visit www.marketdelta.com and search VPOC at top search box, you will get all sorts of good information.