C-pop is short for Chinese pop. Chinese pop is from China, Hong Kong, Taiwan, and other countries near China. C-pop also has subgenres, three as of now to be exact, Mandopop (Mandarin pop) Cantopop (Cantonese pop) and Hokkien pop or T-pop (Taiwanese pop).
This is partly because there is more than one way to speak Chinese. If you don’t understand what I mean you should do some research. It will be quite interesting, I tell you.
Mandopop is sung by many artists from Mainland China but also some from Hong Kong. Even some K-pop groups sing in mandarin like EXO, for example. Cantopop is sung by artists from Hong Kong since that’s the local dialect there. T-pop is sung by artists from Taiwan. Mandopop, Cantopop, and T-pop are all also sung by singers and groups from neighboring and foreign countries.