Materials like concrete, cement and wood absorb water and let it to move through them. This is why the foundation needs to be drained, same as using water proof coatings and the diversion. The water can be kept away from the foundation to avoid moisture in basements.
Water needs to exit the structure around the foundation, otherwise it can damage your house. And always, the building needs to be sufficiently ventilated. Moisture intrusion can cause serious health issues and destroy the structure of the building.
