From ArticleWorld

Security deals with protection in the sense of safety from hostile action. Security is the condition of being protected against danger. In the general sense, it can be said that security is a matter which is ion many ways akin to safety. The difference between the two is that in the case of security, there is an added emphasis on protection from dangers that originate from external sources. It may be said that people or actions that infringe upon the condition of safety are responsible for a breach of security. As a technical term "security" means that something not only is secure but that it has been secured. It may also have the following meaning depending upon the context. It may refer to a condition that results from the establishment and maintenance of protective measures that ensure a state of inviolability from hostile acts or influences. In the case of national security, a condition prevents unauthorized persons from having access to official information that is safeguarded in the interests of nation. In that case, it may be measures taken by a military unit, an activity or installation to protect itself against all acts designed to impair its effectiveness. Experts suggest that security measures improve the likeliness of expectations to be met, and therefore improve security by giving the feeling of a security. With regards to classified matter, there is an expectation of security as long as the classified matter remains secret. It is said that the key problem in defining security is that it is a fuzzy concept that defies constructs. Most security measures involve compromise. Security has to be compared and contrasted with other related concepts like safety, continuity, and reliability. The key difference between security and reliability is that security must take into account the actions of active malcontents that might attempt to cause destruction or a breach of security. It is maintained that people's perception of security is not directly related to the actual security. Another aspect of security is the phenomenon called security theatre in which ineffective security measures such as screening of airline passengers based on predetermined databases are used even when the chances of such measures preventing security breach are rare. According to the critics of such measures, these steps have very little or no bearing on actual security threats. For better understanding, security is to be viewed with respect to certain concepts like risk, threat, countermeasure, defence in depth, and assurance in the effectiveness of security measures.