Using chemiacl combination of fragrance materials with malodour components: this generates a new different molecule with different odour profile thus taking the specific malodour components out of the air.
Physical combination of fragrance raw materials with malodour components ( via hydrogen bonding or Van der Waal forces):creates a spatially different structure combining the malodour ingredients with fragrance ingredients. The new structure binds differently at the odour receptor site eliciting a different non-malodour signal.