Which type of barrier is typically used to deter unauthorized access in physical security?

Perimeter fences and barriers are designed specifically to create a physical barrier that deters unauthorized access to a facility or area. These structures serve as the first line of defense in physical security by making it more difficult for intruders to approach or enter a protected site. They can take various forms, including chain-link fences, walls, and bollards, and are often accompanied by additional security measures like signage or landscaping that enhances their effectiveness.

In contrast, security cameras and alarm systems play crucial roles in monitoring and alerting to potential breaches, but they do not physically prevent access. Locking mechanisms, while effective at securing specific entry points like doors and gates, do not provide the broader protective coverage that perimeter barriers do. Thus, perimeter fences and barriers are essential for establishing a secure perimeter and are the primary means of physically deterring unauthorized individuals from entering sensitive areas.