this means Chinese language and it doesn't matter what dialect it is whether it's Mandarin, Cantonese, or whatever. Chi zhing-zhong is sometimes loosely used in reference to Oriental culture just like how the word Chivheti is used in the context of Occidental culture.
However, zhing-zhong (or rather zhang-zheng-zhing-zhong-zhung) on its own refers to anything that was made in The People's Republic of China. And finally, cheaply made Chinese products are referred to with the following catchphrase phrases:
|Zhange zhiri zhako zhaa zhangu||What was yours it's now mine|
|Zhange zhiri zhake zhaa zhedu||What was his (or hers) it's now ours|
|Change chiri chako chave changu||What used to be yours it's now mine|