They are much the same thing in many discussions of aging. The generally agreed upon definition of aging in the geroscience community is that it is an increase in risk of death due to intrinsic causes. You are more aged if you have a higher risk of death, and you are aging if your risk of death due to intrinsic causes is higher today than it was yesterday.<p>Then we can get into primary aging (think of the SENS list of damage, internal mechanisms like mitochondrial damage and cross-link deposition) versus secondary aging (think of smoking and getting fat, things that increase the pace of damage accumulation), and further complexities after that. But the core definition of aging is very simple, and it is all about dying.