Mashk is a word used in some parts of the world to describe a special kind of traditional water container made of animal skin, usually from a goat, sheep or cow. It's like a big leather bag that can hold water or other liquids, kind of like a big water bottle.
People have been using mashks for centuries because they are natural and readily available, and they can be a more practical way of storing and carrying water than other materials like plastic or metal. The skin of the animal is first tanned using a special process to make it soft and flexible, and then it is sewn together to make the bag.
Mashks can be found in many different shapes and sizes, and they come with strings or straps that allow people to carry them around easily. In some cultures, they're even decorated with beautiful designs and patterns.
For a 5-year-old, it's like having your own cool animal-skin water bottle that you can take with you whenever you need a drink, and it's been around for a long, long time!