profession vs occupation

What's the difference between 

 *PROFESSION* is an activity when a person is paid for his 
particular skill and his deep knowledge. 
 PROFESSION needs a specialised training and
Example: Doctors, Engineers, Teachers, Lawyers, Chartered 
Accountants etc.

 *OCCUPATION* is an activity when a person is not paid 
for their knowledge, but only for what they produce.
 OCCUPATION doesn't need any special training.
Example: Drivers, shopkeepers, clerks, accountants, etc.

 *ABKO English Academy*