Mold needs three things: spores (always in the air), an organic food source (drywall paper, wood, dust), and moisture. You cannot remove the first two from a home, so controlling moisture is the entire game. That is why restoration focuses on drying the structure to a verified moisture level, not just mopping up water.
The highest-risk spots are the ones you cannot see: behind baseboards, under flooring, inside wall cavities, and in insulation. A surface that feels dry can sit on top of saturated material. Professionals confirm dryness with penetrating and non-penetrating moisture meters and thermal imaging.
Handled quickly, most water losses never become mold losses. Handled slowly, a simple dry-out turns into a containment-and-removal project on the same insurance claim.