[1] Due to improvements in technology, it is necessary to make a distinction between a VMS and the built-in features of modern network based security cameras.
Many modern network cameras offer internal capabilities to record and review video directly themselves via a web browser and without the use of a VMS.
A VMS may provide the ability to monitor alarm inputs and act on them in some manner, including: Alarm inputs and outputs can be handled through separate interface components such as: A VMS may also provide the ability to remotely control pan-tilt-zoom (PTZ) cameras, which can be remotely rotated, titled, and zoomed, thereby allowing a single camera to monitor a very large area while also providing detailed views of specific areas of interest.
Moving cameras have a tendency to fail over time due to wear of the drive motors, belts, and bearings.
When mounted overhead pointing straight down, part of the viewed space appears sideways or upside-down on the VMS.
A hybrid system provides for a lower cost transition between analog and digital cameras, allowing the VMS to accept input from either video source type.
A VMS may offer the ability to be linked to the output of an electronic cash register, displaying the information printed on a sales receipt as text overlaying the camera image.
However the spherical view causes angular distortion of straight lines, giving objects a strange bulged and deformed appearance.
Some manufacturers such as Oncam and Panasonic have developed their own custom techniques, and need to provide decoding libraries to the VMS programmers to support their cameras.
Alternately a high performance dewarping method called Immervision has been developed, which also makes use of a special lens geometry to redistribute pixels in a more efficient manner.
A feature of some newer VMS is the capability to show multiple camera views from a single recorded stream.
A single camera with a very wide or high resolution field of view is capable of covering two or more areas of interest.