VCR then DVR and now NVR,HD-SDI DVR, HD-CVI DVR, HD-TVI DVR
VCR are history they are gone lets not waste time on them.
DVR is a Analog device which records on a Hard Drive. The latest video compression on them is H.264 and most them even support 4 TB Hard Drive.Video can be remote viewed via internet enabled device like Laptop,PC, Mac, iPhone,android etc
NVR’s are just like DVR’s but you have use IP cameras. Compatibility and bandwidth to major problems with NVR’s
HD-SDI DVR are just like Analog DVR the biggest advantage is the picture quality mostly 1080p 2 MP. Long runs of cable like over 310 feet can be a big problem. Repeaters can be used to solve the issue. Always use good quality cable for HD-SDI installation, using premade cable, baluns etc is a bad idea.
HD-TVI is just like HD-SDI just cheaper in price.