A network hard disk recorder, also known as an nvr (network video recorder), is a digital device used to record, store, and manage video footage from ip (network) cameras.
specifications
video input: 4 / 8 / 16 channels (depending on model)
video compression: h.264 / h.265
recording resolution: up to 1080p / 4mp / 5mp / 4k
storage: 1 or more sata hdd slots (up to 8tb or more)
network interface: rj45 ethernet port (10/100 mbps)
-video output: hdmi / vga for monitor display
-audio i/o: 1 or 2 channels (optional)
-remote access: mobile app & pc (via ip or cloud)
-power supply: dc 12v / 2a (typical)
-functions: live view, playback, backup, motion detection, alarm