Low volume nodes appear as narrow waists in the profile. Few contracts changed hands there because the price was unacceptable to one side, so the market passed through rather than settling.
Traders use them two ways: as places where price is likely to accelerate once entered, and as edges of value where a rejection can be expected on the first approach. Stops placed just beyond a low volume node are usually poor, because price moves through the region fast.
The relationship to single-prints is close, both describing thin areas, and to imbalance in market-structure vocabulary. The same observation keeps reappearing under different names, which is worth noticing before stacking three tools that measure one thing.
Related: high-volume-node, volume-profile, single-prints, imbalance, value-area