What is the difference between damp proofing and waterproofing?

Damp proofing generally refers to resisting ground moisture (dampness) that is not under pressure, such as rising damp in walls above ground. Waterproofing refers to resisting liquid water under hydrostatic pressure, such as in basements below the water table. A Damp Proof Course (DPC) stops capillary action, whereas a Waterproofing System (like tanking) forms a complete barrier against pressurized water. Confusing the two leads to basement failures.