Okay, so imagine you have a toy box with a bunch of different toys inside. Your mom tells you that you need to keep your toys organized, so you decide to separate them into different groups: dolls in one group, cars in another, blocks in another, and so on.
A damin is kind of like a toy box for information on a computer. Just like you sorted your toys into different groups, a damin allows you to sort all the information on your computer into different groups based on what it is.
So if you have a bunch of pictures of animals on your computer (just like you had a bunch of dolls in your toy box), you can create a damin specifically for all those animal pictures. This makes it really easy to find them again later when you want to look at them or show them to someone else.
Overall, a damin is a way of organizing all the stuff on your computer so that you can find everything easily and quickly, just like how you organized your toys in your toy box.