Beneficiaries of security may be of persons and social groups, objects and institutions, ecosystems or any other entity or phenomenon vulnerable to unwanted change. Security mostly refers to protection from hostile forces, but it has a wide range of other senses: for example, as the absence of harm; as the presence of an essential good; as resilience against potential damage or harm; as secrecy; as containment; and as a state of mind. The term is also used to refer to acts and systems whose purpose may be to provide security.