• What do you do?
This question means “What is your job/profession?”
• I’m a student.
• I work in a bank.
• I’m unemployed at the moment.
• I run my own business.
The word “run” means you are the primary person responsible for operating the business.
•I’m retired now. I used to be an engineer.
“Retired” means you have stopped working (usually after you are 60 or 65 years old).