Tech Term : DVR and NVR as they relate to security cameras: When you hear the term DVR you may wonder if you remembered to set your home DVR to record your favorite show. However, when we use DVR we are talking about security for your home or business. In this context the DVR unit records video from digital cameras connected by coaxial cable. A NVR does the same thing only instead it connects to your existing network and uses IP cameras with CAT5 data wiring. A NVR system is usually licensed for a certain number of cameras with the option to add additional licensed cameras. A DVR unit has a number of actual ports meaning there is set number of cameras the DVR system can handle. Because of this the NVR system offers more flexibility.