Different countries or regions follow different method […]
Different countries or regions follow different method of applying model numbers to cables.
RG-6, Rg-59, RG-11 is commonly used in USA and other countries who follow US system of units, measure and model numbers.
3C-2V, 5D, 7D etc is commonly used in China and other countries who follow Chinese system of units, measure and model numbers.
The application and type of cable is same. RG-59 and 3C-2V are both 75 ohms cables. The size of conductor and Outer diameter may vary a little.
A quick internet dive into researching the differences of these cable specifications seems to indicate that 3C-2V (a Japanese standardization for a low end cable) is just lower than RG-59 in terms of “quality” (conductor and shielding wire sizes, thickness of insulator, and protecting jacket).
These differences change the cables ability to handle certain frequencies and at different distances, control signal attenuation, electrical noise ingress, flexibility of the overall cable and its durability.
If you consider the many nuances of your installation variables you can choose the best cable for your run.
If you’re running a massive length of cable through a condominium, passing many sources of interfering signal or power lines, you’ll need a cable that can handle a signal that long with as little attenuation as possible or signal boosted periodically to cope with the loss and durable enough for the run, and shielded sufficiently.
If you’re just running a wire from a shop camera down a few feet to a nearby monitor or DVR, passing by very few interference sources, you might be able to get away with far less of a cable specification.