H Shares: Issued by companies incorporated in China; they trade on the Hong Kong exchange in Hong Kong dollars or other currencies. ("H" stands for Hong Kong.)
A Shares: Issued by Chinese companies and denominated in renminbi. They are sold on the Shanghai and Shenzhen exchanges almost exclusively to domestic investors.
B Shares: Issued by Chinese companies and trade in U.S. dollars in Shanghai and in Hong Kong dollars in Shenzhen. They are sold to foreign investors and to some domestic investors who have foreign currency accounts.
Hong Kong shares: Issued by businesses that are listed in Hong Kong and focus the bulk of their activities either in Hong Kong or elsewhere in the world.
China Plays: Hong Kong-listed companies that can be owned, established, and listed by anyone, anywhere; they derive a significant portion of their business from China.