Freeze drying is the process of freezing the contents and removing pressure until the moisture is turned to vapor. This process removes 99% of the moisture and preserves approximately 97% of the nutrients vs Dehydrating that only removes 85-95% of the nutrients and preserves 60-75% of the nutrients. Due to the percentage of moisture withdrawn through freeze drying, whats left of your food is incredibly light weight (ideal for travel, backpacking, storage, and typically stable for up to 25 years.