Cora wants to know the difference between safety and security.
Safety and security and their adjectives safe and secure are often used in tandem, as in the hymn:
Leaning, leaning, safe and secure from all alarm
Leaning, leaning, leaning on the everlasting arms
These definitions from the OED treat them as synonyms:
safety: a. The state of being safe; exemption from hurt or injury; freedom from danger. safety chain, a chain providing additional security
security: The condition of being protected from or not exposed to danger; safety.
Nevertheless, the words differ in connotation and writers will weigh the context when deciding which to use.
Safe and safety, for example, push emotional buttons that secure and security don’t. We speak of national security, but personal safety. Threatened townspeople seek the security of castle walls, but a frightened child runs to the safety of her father’s arms.
Security surrounds, but safety enfolds. Perhaps the lingering differences between the words can be found in their differing etymologies.
Safe comes from Latin salvus, “uninjured, healthy. It’s related to salus, “good health.”
Secure comes from Latin securus, “without care,” from se, “free from,” and cura, “care.”
To my mind, security suggests freedom from worries that derive from knowing that certain external safeguards are in place and that I can rely on them to protect me and my property. Safety is a richer word that includes an inner certainty that all is well. In a sense, security is external, while safety is internal.