The old technology CCTV systems used the (now defunct) analogue method to record images onto VHS tapes from a multiplexer or similar device. This of course meant keeping a stock of tapes which needed to be changed frequently. The resolution of the recorded images was of very bad quality.
Nowadays, the “new” technology (10 years old at least) uses DVRs (Digital Video Recorders) which process and stores video images digitally onto a Hard Disk Drive, therefore enabling long recording times with minimum maintenance and provides clear, high resolution images without degradation of image quality.
Additionally, DVRs have real time image transmission and remote control capability over the Internet. IP CCTV with associated DVRs or NVRs is regarded as the most effective video monitoring system for any company that has a network or network capability.