For a low resolution system, a normal TV can be used but it does not have the resolution of a CCTV Monitor. A typical TV has resolution of about 300-350TVL. A good CCTV monitor will have resolution of 500TVL upwards. CCTV monitors are also built for the purpose.
A standard PC TFT (LCD) display will only have VGA connector and therefore cannot directly be used as composite video monitor (CCTV Monitor). A TFT that is suitable as a CCTV monitor will have direct video input without a VGA to video converter. These TFTs are more expensive.