Human activities are primarily classified into two categories, i.e. economic activities, and non-economic activities. Economic Activities are the activities conducted with an aim of earning money or livelihood. Further, these activities are sub-divided into business, profession and employment. There is a huge difference between business and profession in the sense that there is no minimum qualification required for starting a business. It means an activity that is related to buying and selling of goods.
On the other hand, a profession is nothing but a paid occupation that requires a person to be formally qualified, expert and trained in a particular field to be called as a professional. Take a read at this article to know more on the two topics.