The POC is the price the market spent the most time and volume agreeing on. It acts as a magnet on pullbacks and as a reference for whether price is accepted above or below value.
A session POC, a weekly POC, and a composite POC over months are all used; the longer the period, the more significant the level.
Example: on a day where a stock traded $99 to $103, 22% of the volume printed at $101.20. That is the POC. A return to $101.20 next morning is a common place to see buyers and sellers fight.
Related: volume-profile, value-area, support, resistance