The stock main board is a stock trading market dominated by traditional industries, and the second board is an entrepreneurial version with low listing standards, mainly serving high-tech and high-growth small and medium-sized enterprises. At present, China is launching, and Nasdaq in the United States is the most famous GEM in the world.

The third board is a stock transfer system. The third board market in China is quite special, trading all the stocks delisted from the main board. For example, some enterprises have been forced to withdraw from the stock main board after years of losses, and they can continue trading in the third board market.

Small and medium-sized board is relative to the stock main board market. The main stock market in China includes Shenzhen Stock Exchange and Shanghai Stock Exchange. Some enterprises can't meet the requirements of the main board market and can only be listed in the small and medium-sized board market. Small and medium-sized board market is the transition of GEM, and the market code of small and medium-sized board in China begins with 002.