what is A-shares and b-shares of the China's Stock Market

In May 1992, the chinese State Council issued regulation that categorized the shares of a shareholding enterprise into three types:
(1) state and legal person shares, which are owned either directly or
indirectly by the state and which cannot be traded freely on the stock
exchanges but can be transferred only with administrative approval;
(2) A-shares, which are yuan-denominated and are available for trad-
ing by domestic private shareholders on the stock exchanges; and (3)
B-shares, which are available for trading by foreign investors in for-
eign currencies on the stock exchanges. This regulation effectively
institutionalized a unique feature of China's stock market¡ªthe crea-
tion of three distinct markets for the stocks of a listed enterprise,
namely, the one-way transfer market for state-owned shares, the A-
shares market for domestic private shareholders, and the B-sharesmarket for foreign investors