CCTV stands for High Definition Composite Video Interface and
can sometimes be referred to as high definition analog CCTV. It is a
relatively new technology that offers the benefits of high definition
recording without all of the costs associated with a full IP CCTV system
HDCVI is a revolutionary technology that can transmit high definition video quality over standard RG59 Siamese cable.HDCVI cameras. The next generation of HD security. HD-CVI cameras only works with HD-CVI compatible DVRs.HD-CVI cameras available in 1080P and 2MP also. All-in-one cameras support HD-CVI also. Hybrid CVI DVR can support your Analog cameras. Tribrid HD-CVI DVR can support IP cameras, use Dahua brand to avoid conflicts and compatibility. IP cameras over 2 MP will work but the image quality will be 2 MP because the HD-CVI DVR can support Maximum 2 MP.
If you are using all IP camera use a NVR , they even come with built in POE. Some brands like Dahua and Hikvision are really affordable. They come with 3 years warranty and support from USA.