A preparation method for food so that it can be kept for longer periods of time without spoiling. Preserving can be accomplished in a number of ways including refrigeration, freezing, canning, salting, smoking, freeze-drying, dehydrating and pickling.

keeping food so that it will not spoil; three ways are freezing, canning, and drying.

saving from harm or loss; "serves a conserving function"

A function between posets and is said to preserve suprema (joins), if, for all subsets of that have a supremum sup in , we find that sup{(): in } exists and is equal to (sup ). Such a function is also called join-preserving. Analogously, one says that preserves finite, non-empty, directed, or arbitrary joins (or meets). The converse property is called join-reflecting.