Ordinary open-end fund: use the fund account, purchase off-site, and charge subscription fees.

LOF, ETF: fund account or stock account can be used. You can buy on-site or off-site (just like buying stocks), and charge a commission, with a single transaction not exceeding 0.3%.

Closed-end fund: use stock account, buy in stock (like buying stocks), and charge commission, with a single transaction not exceeding 0.3.