This refers to how a paint will stand up to traffic. The higher the traffic the more the wall requires durability. Think about...
• handrail going up the stairs
• mud rooms where the dogs come in all wet
• kitchens if there is a lot of grease
• kid’s walls
Those walls that are going to take a beating need a paint that can handle it. Flat paint (more about that later) is not durable but paints that are designed for higher traffic areas are. Know what you need. You don’t need a durable paint on a ceiling unless you use a lot of grease in the kitchen and need to wash your ceilings.