Freeze-drying is a food preservation method that removes moisture from items while keeping their structure and nutrients intact. The process involves freezing the food and then placing it in a vacuum chamber, where the ice turns directly into vapor without becoming liquid. This technique helps extend the shelf life of various foods, including fruits, vegetables, and meals. The result of freeze-drying is lightweight, shelf-stable products that can be easily rehydrated by adding water. Commonly used in camping and emergency food supplies, freeze-dried foods are popular for their convenience and long-lasting quality, making them a practical choice for outdoor enthusiasts and survivalists.