The major difference between waterproofing and damp proofing is that damp proofing is designed to keep out moisture from the soil, while waterproofing keeps out liquid water and moisture.
The confusion stems from the fact that dampproofed buildings are often referred to as being waterproof. However, regardless of the differences, waterproofing requires the same care as damp proofing when it comes to drains, pipes, and surface treatments.