Physical security is the protection of buildings, sites and people, as opposed to the protection of computer systems. It covers the office door, the lobby camera, the airport checkpoint and the safety of employees during an emergency. Most of it now runs on software.
Consider one working day for a software engineer in Bhubaneswar. In the morning, she taps her ID card at the turnstile of her office. A reader checks the card, and physical access control software decides whether that card may pass that gate at that hour. A camera above the turnstile records her entry. Its video goes to a video management system (VMS), which stores the recordings of every camera in the building and lets the security team search them. Video analytics software checks the same video for problems, such as a second person walking through on her tap.
In the evening, she flies to Delhi. At the airport, her bag goes through an X-ray machine run by security screening systems. That night, heavy rain floods the road to her office. She gets an SMS that asks her to work from home and to reply that she is safe. That message came from critical event management software. The same week, her company's chief executive gives a talk at a large conference. The company's security team checks for threats against him with protective intelligence software.
Why does this site cover physical security next to cybersecurity? Because the two fields have merged in three ways. First, one company identity system often issues both the door card and the computer login. So when an employee leaves, one change switches off both. This is converged access control. Second, AI models now check camera video in the same way that other AI models check network traffic. Third, a corporate security team reads the same threat reports as the analysts who guard the company's computers in the security operations centre (SOC).
The biggest change is that a guard no longer has to watch every screen. Software checks every camera and door alarm first, and passes on only the alarms that need a person. This sorting is called alert triage.