The acronym NVR in video surveillance stands for "Network Video Recorder." An NVR is a specialized device used to record and manage video streams from IP cameras over a network. It is essential for monitoring and archiving footage, providing features such as remote access, playback, and analytics. NVRs differ from traditional DVRs by offering higher scalability and flexibility in modern surveillance systems, making them vital for enhancing security in various environments like businesses and public spaces.