A waterskin is a container designed for carrying drinking water while traveling. It is also known by different names such as water bag, canteen, flask, and water bottle. The term 'canteen' derives from the military's use of a container to store and distribute water. A water bag is typically made from animal hides or treated materials such as nylon and plastic. A flask is a small water bottle that often fits into a backpack. Water bottles are the most commonly used containers and come in different shapes and sizes. Regardless of the name, the essential purpose is to hydrate during travel, and all these containers serve this crucial function.