Diffusion refers to the dispersion of inhaled smoke into myriad smaller sized bubbles to increase cumulative surface area exposed to water inside a bong or dab rig. This expanded surface contact efficiently filters, conditions and cools smoke as it percolates before inhalation. Strategically designed percolators and diffusers physically break up smoke into much tinier bubbles compared to inhaling large, unfiltered plumes of raw smoke alone. The smaller bubbles created possess a greater total surface area versus fewer large bubbles of equivalent volume. This greater collective surface area makes the cooling water far more effective and efficient at removing heat and undesirable components. In turn, the resulting cooled, purified smoke enables users to comfortably inhale significantly larger hit volumes without irritation or coughing. However, some THC and terpenes do get absorbed into the water as an inherent tradeoff of increased diffusion. So the superior smoothness and clarity comes at the partial sacrifice of losing a small percentage of overall potency. Finding the ideal diffusion balance for individual tastes maximizes smoking enjoyment.