Different names for the same thing. This type of brush is used in oil based paints only.

A natural will also come with a yellow looking bristles too,as chinese will always be black,the black bristles are best used for clears (varnish,poly,) oil or latex clears, it does not hold enough stain to do any type of staining or painting with it.

They both come the backs of chinese pigs and one have been dyed and the other has not.