商业(commerce) trade of merchandise

生意(business) more than merchandise trade, all industry make money could be business. like massage which provides service to the customer, plus 生意 could be used to describe a business is profitable or not

by using 生意好/不好

for e.g. 我们按摩院的生意很好 our message parlor is a profitable business

- 余世明

 in Chinese , 生意 always means sell and sold , but 商业 means more , include corporation or resource exchange or something else

- Shuai Fu