With just one CAT5e cable to run between NVR and cameras makes Hikvision IP systems fast and neat to install. No need for separate power supply or bulky coaxial cables.
For upgrades to High Definition ( HD), existing cables are likely to be coaxial cable ( like TV aerial cable ). In this situation where re-cabling to CAT5e would be costly, you can use a hybrid recorder. This will allow you to use HD TVI cameras on the coaxial cable and new ones can be wired in CAT5e.