Define perimeter security in physical security measures.

Perimeter security in physical security measures refers to the protection of the outer boundaries of a facility to prevent unauthorized access. This is crucial because the perimeter serves as the first line of defense against potential intruders and unauthorized visitors. Effective perimeter security typically employs a combination of physical barriers, such as fences, walls, and gates, alongside technological measures, such as surveillance cameras, alarms, and motion detectors.

By establishing a secure perimeter, organizations can deter potential threats from entering the premises and can monitor and control access points. This strengthens the overall security posture of the facility, ensuring that any potential breaches can be detected early and responded to swiftly, thereby safeguarding internal resources and assets.