Individual stocks form plates, and plates produce indexes. The public investment portfolio established by purchasing the constituent stocks of the index is the index fund.

For example, Shanghai and Shenzhen 60000 1 ~ 600 150 and 0000 1 ~ 000 150 and 150 respectively form the Shanghai and Shenzhen 300 Index, and publicly raise funds to buy these 300 shares, which is the Shanghai and Shenzhen 300 Index Fund. (That's probably what it means. )