A video management system (VMS) is the software that receives the video from every security camera in a building or site, records it, and lets the security team watch it live and search the recordings later. It is the main software behind a building's CCTV, or closed-circuit television, the term most Indians use for security cameras.
A VMS does four jobs. It receives the video from each camera over the building's network. It records the video and keeps it for a set number of days, often 30 to 90. It shows live video on the screens in the security room, or on a large video wall. And it lets an officer search the recordings by camera, date and time.
Storage is the main cost. One camera that records full-HD video all day can produce about 20 GB of data a day. A site with hundreds of cameras would fill its disks in days. So most systems compress the video heavily, record at a lower quality when nothing moves, and keep full quality only when something does.
Here is a typical case. A hospital in Bhopal has 250 cameras. At 4 p.m., a patient's relative reports that her phone was stolen from a waiting area at about 3 p.m. The security officer opens camera 41, which covers that waiting area, and asks the VMS for every moment between 2:45 and 3:15 p.m. when something moved near the third row of chairs. In a few minutes, he finds a man picking up the phone at 2:58 p.m. He then follows the man on the cameras along the corridor and at the main gate. He exports a three-minute clip for the police. The VMS stamps the clip with a code that shows later that nobody has edited it.
A VMS is often linked to physical access control. Each card tap at a door is stored with the video from that door. So an officer can search "every refused tap at the pharmacy store this week" and watch each one.
Traditionally, the recordings were kept on a recorder in the building's own server room. Newer systems keep them in the cloud, as a service paid for every month. This is software as a service (SaaS). The video is protected with encryption on its way to the cloud. Before the cameras are installed, security system design software plans where each camera goes and what it can see.
How is a VMS different from video analytics? A VMS records and finds video when a person asks for it. Video analytics watches the video by itself and raises an alert when it sees a problem.