It is the process in which an individual or group of people or facilities are protected against external threat which can cause physical harm to the people. It generally involves the armed personnel and modern gadgets that are used to detect threats as well as to counter them.
The scope of the term security is quite narrow and only caters to security of people or installations. It does not take into account the otherwise well being of individuals.
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It is a fairly broad term and not only does it take into account the physical protection of individuals or facilities, but also the protection of other kinds.
It includes the well being against external threats as well as the health of the given person.
Protection can be against threats, germs, external contaminants as well as other issues. The term is also used for non-living beings.
For example, a computer can be protected against viruses in order to keep it in proper working order.
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