In both cases, you don’t suffer from the disease being in your body, but it’s still there. So why would someone be considered one vs the other?
When you’re immune, you’re body is able to fight off and destroy the virus completely. When you’re asymptomatic, you just don’t feel the virus, but it’s still active in your body. In short, when asymptomatic, you’re still contageous, and when immune, you’re not.
I’m not a medical expert. Immunity means the body has the tools needed to successfully fight off an infection or toxin, etc. Asymptomatic people can carry the infection without being affected by it.
If you are immune to a disease then you have already had the diseases and have now built up resistive forces called antibodies that will now fight virus if it tries to enter your system again. Once you’ve had a specific strain of a virus you are theoretically immune to it because your body should have already made those barriers when you fought it previously. If you are asymptomatic then you currently have the disease but it is so mild that your body is not producing any symptoms. Your body fights it off before you even know you have anything resulting in you never having any symptoms. You probably experience many viruses like this over the course of a year that you never know you have.