A security guard (or security officer) is a person who is paid to protect property, assets, or people. Security guards are usually privately and formally employed personnel. Often, security officers are uniformed and act to protect property by maintaining a high visibility presence to deter illegal and inappropriate actions, observing (either directly, through patrols, or by watching alarm systems or video cameras) for signs of crime, fire or disorder; then taking action and reporting any incidents to their client and emergency services as appropriate. - Source: Wikipedia