Why is sugar used as preservative?

Sugar is used to preserve food by reducing the amount of moisture in the food. This prevents the growth of microorganisms that cause food spoilage. In high sugar concentrations, bacteria and fungi struggle to grow and reproduce due to the osmotic pressure and decreased water availability. This can help extend the shelf life of certain foods, such as jams and jellies. However, it is important to note that sugar alone is not a reliable preservative and can only be used effectively in specific conditions and food types.