A good question, Gian. Quite simply, the answer is this : moist is a positive quality, while damp is a negative one. Here are some examples: A moist cake is nicer to eat than a dry one. Moist skin is softer to stroke than dry skin. It's better for the plants in your garden if the soil is moist rather than dry. You see? These are all good things. By contrast, 'damp' is cold and unpleasant. It is better for your health to live in a dry climate like Southern Italy than a damp one like Ireland. It's not nice to put on laundry while it's still damp - it's much better to make sure that it is nice and dry. So, as you can see, it has nothing to do with actual levels of moisture. The difference is context and attitude. And here's another one for free. Don't make the mistake of thinking that 'humid' has the same meaning as either of these words. It doesn't. It describes a particular climate. 'Humid' refers to a hot climate with a high degree of moisture in the air. The Brazilian rainforest is humid. England is damp.

To me, both are wet, but damp, is always bad. (damp house, etc) whereas moist can be positive (moist cake - in other words NOT dry).

They have the same meaning - slightly wet - but many people don't like the word moist. I don't know why, but there are a lot of people who think it's gross to call things "moist." So, you should probably use the word damp.

i think they mean basically the same. but i heard it quite often that people use moist for food, whereas damp for places.