https://DevOpsCloud.io -- Cloud Monk Losang Jinpa, Ph.D., MCSE/MCT, GitOps DevOps Engineer

A security guard (also known as a security officer, security inspector, factory guard, or protective agent) is a person employed by an organisation or individual to protect their employer's assets (property, people, equipment, money, etc.) from a variety of hazards (such as crime, waste, damages, unsafe worker behavior, etc.) by enforcing preventative measures. Security guards do this by maintaining a high-visibility presence to deter illegal and inappropriate actions, looking (either directly through patrols, or indirectly by monitoring alarm systems or video surveillance cameras) for signs of crime or other hazards (such as a fire), taking action to minimize damage (such as warning and escorting trespassers off property), and reporting any incidents to their clients and emergency services (such as the police or emergency medical services), as appropriate.

Security guards are generally uniformed to represent their lawful authority to protect private property. Security guards are generally governed by legal regulations that set out eligibility requirements (such as a criminal record check) and the authority permitted to them in a given jurisdiction. The authorities permitted for security guards vary by country and subnational jurisdiction. Security guards are hired by a range of organizations, including businesses, government departments and agencies, and not-for-profit organizations (e.g., churches and charitable organizations).

Until the 1980s, the term watchman was more commonly used for this function, a usage dating back at least to the Middle Ages. This term was carried over to North America, where it was interchangeable with night watchman until modern security-based titles replaced both terms. Security guards are sometimes regarded as fulfilling a private policing function.