What is the function of a DVR in video surveillance?

The function of a DVR, or Digital Video Recorder, in video surveillance is primarily to record and store digital video. This device captures video footage from surveillance cameras, processes it, and stores it on a hard drive or other storage medium. The digital format allows for various functionalities, such as easy retrieval, searching through footage, and backup options.

While other options mention functionalities related to video surveillance systems, they do not accurately describe the main role of a DVR. For instance, displaying video transmitted from cameras is typically done by a monitor or a separate display unit, while transmitting video through a local area network pertains more to network video recorders (NVRs) or different systems altogether. Storing analog video footage is not applicable to DVRs, as they are designed specifically for digital video formats. Therefore, the primary and distinctive function of the DVR in this context remains its ability to record and store digital video.