What is the different between major and minor surgery?

Difference is -: Major surgery is when I am having a surgical procedure performed. Minor surgery is when you are having the procedure performed. Any surgical procedure carries some degree of risk. From a risk standpoint, the greater the risks, the more major the surgery.

Depends: The difference is the level of stress experienced by patient's body in relation to the compromising cardio-vascular function. Surgeries on extremities will be considered minor, when abdominal, thoracic or brain surgery will be considered major. Variations in interpretation are very common.