Security - Security is the degree of protection against danger, loss, and criminals. Individuals or actions that encroach upon the condition of protection are responsible for a "breach of security."

A condition that results from the establishment and maintenance of protective measures that ensure a state of inviolability from hostile acts or influences.

Security has to be compared and contrasted with other related concepts: Safety, continuity, reliability. The key difference between security and reliability is that security must take into account the actions of people attempting to cause destruction.