Canteen carrier refers to a container in which water or other drinks are stored, especially in a camp or a military base. The term has a few synonyms that can be used interchangeably, including water bottle holder, flask carrier, hydration pack, and beverage pouch. A water bottle holder is the simplest form of the container, which is usually attached to backpacks or belts and holds water bottles securely for easy access. A flask carrier is a small bag or container built to carry a flask, which can be used for carrying hot or cold beverages. A hydration pack is a backpack that features a bladder for carrying water, while a beverage pouch is a lightweight container for storing drinks.